HomeMy WebLinkAbout2014 07 28 Public Hearing 502 Second Reading of Ordinance 2014-13 Billboards/EMC RevisionsCOMMISSION AGENDA
ITEM 502
REQUEST:
Informational
Consent
Public Hearings
X
Regular
July 28, 2014 KS RS
Regular Meeting City Manager Department
The Community Development Department — Planning Division requests the City
Commission approve Ordinance 2014 -13, which proposes to amend the City's regulations
regarding off - premises signs, commonly referred to as billboards, and electronic message
centers.
SYNOPSIS:
On March 10, 2014, the City Commission approved Ordinance 2013 -11, which amended
Section 16 -77 of the Code of Ordinances to permit the reconstruction of billboards that are
located only along the U.S. 17 -92 corridor into digital billboards which utilize electronic
message display technology. Ordinance 2014 -13 proposes to amend Ordinance 2013 -11 to
permit the reconstruction of billboards along the U.S. 17 -92 corridor on other properties
abutting U.S. 17 -92 which are under the same ownership as the property upon which the
existing billboard in currently located.
Additionally, Ordinance 2014 -13 proposes to amend Section 16 -81 of the Code of
Ordinances, regarding electronic message center signs. This amendment proposes to reduce
hold times from eight (8) seconds to two (2) seconds when static messages transition to
another image, and proposes to amend transition methods and transition times for messages
on electronic message center signs.
Public Hearings 502 PAGE 1 OF 6 - July 28, 2014
CONSIDERATIONS:
APPLICANT AND PROPERTY INFORMATION:
• Applicant name and address and authorized representative: City of Winter Springs,
1126 East State Road 434, Winter Springs, FL 32708.
• Property owner's name(s): Not applicable
• Property addresses: Not applicable
• Property Parcel ID numbers: Not applicable
. Current FLUM Designations: Not applicable
. Current Zoning Designations: Not applicable
. Previously Approved Development permits such as conditional use, waiver, or
variance (if any): Not applicable
. Development Agreements (if any): Not applicable
. Pending Code Enforcement Actions (if any): Not applicable
. City Liens if any : Not applicable
APPLICABLE LAW, PUBLIC POLICY, AND EVENTS
Florida Statutes 163.2511- 163.3246: (Provides that land development regulations for
municipal planning be consistent with the Comprehensive Plan).
Florida Statute 166.041 Procedures for adoption of ordinances and resolutions.
Winter Springs Charter Article IV. Governing Body.
Section 4.06. General powers and duties.
Section 4.15. Ordinances in General.
City of Winter Springs Comprehensive Plan
Winter Springs Code of Ordinances, Chapter 16 signs, Section 16 -77 - outdoor
display /billboards - off - premises signs prohibited
Winter Springs Code of Ordinances, Chapter 16 signs, Section 16 -81 - Changeable copy
signs; electronic message centers.
DISCUSSION:
BILLBOARDS
Ordinance 2013 -11 amended Section 16 -77 of the Code of Ordinances to permit the
reconstruction of existing billboards that are located only along the U.S. 17 -92 corridor into
digital billboards which utilize electronic message display technology. Currently, there are
two existing billboards located on U.S. 17 -92: 1) the southeast corner of the intersection of
U.S. 17 -92 and Shepard Road, and 2) the recently approved Racetrac site, which permitted
an existing billboard to be raised to a higher height by an approved Annexation Agreement.
The City is currently negotiating a request to reconstruct a legally non - conforming billboard
into a digital billboard with electronic message display technology that is located on the
U.S. 17 -92 corridor. This billboard is located at the southeast corner of the intersection of
Public Hearings 502 PAGE 2 OF 6 - July 28, 2014
U.S. 17 -92 and Shepard Road. It is currently held up by six (6) wooden poles and was
constructed prior to the advent of electronic message display technology. The parcel where
the existing billboard is located has overhead power lines that will prevent the
reconstruction of the billboard on the same parcel. Due to this issue, the property owner has
indicated a desire to reconstruct the billboard on an adjacent parcel which abuts U.S. 17 -92
that is under the same ownership. This parcel does not have interference issues with
overhead power lines, and will permit the reconstruction of the billboard in accordance with
all criteria that was adopted in Ordinance 2013 -11. In addition, the relocation will place the
base of the billboard behind a 6 -foot tall fence thereby concealing the base of the structure
from the view of passing motorists.
In an effort to resolve this situation and provide certain options for the billboard property
owners and the City, Ordinance 2014 -13 proposes to amend Ordinance 2013 -11 to permit
the reconstruction of billboards along the U.S. 17 -92 corridor on other property abutting
U.S. 17 -92 which is under the same ownership as the property upon which the existing
billboard in currently located, provided the relocation of a billboard more adequately
promotes the visual aesthetics and safety of vehicular traffic along the U.S. 17 -92 corridor.
ELECTRONIC MESSAGE CENTERS (EMC)
Ordinance 2014 -13 proposes to amend Section 16 -81 of the Code of Ordinances, regarding
electronic message center signs. This amendment proposes to reduce hold times from eight
(8) seconds to two (2) seconds when static messages transition to another image, and
proposes to amend transition methods to allow for other commonly used transitions
including fade, dissolve, scroll and fly -in. Further, the amendment proposes to set a
maximum speed for transition times of the amended transition methods to a rate of no faster
than the "medium" speed program setting as reflected in a scrolling rate.
STAFF FINDINGS
Recently, in the interest of maximizing information provided to the public, city staff
conducted a non - scientific evaluation over a ninety (90) day period to determine the
effectiveness of additional message transitions on the City Hall EMC (alongside State Road
434). Currently, Section 16 -81 of the Code for Changeable Copy Signs and EMC's allows
for a `static' image with an eight (8) second hold time to be displayed. This requirement has
limited the intended viewing audience to approximately two (2) short message subjects
during a typical drive -by at 45 mph.
In an effort to increase the amount of information viewed by each driver during the
evaluation period, staff reprogrammed the City Hall EMC to utilize various industry
standard message transitions including scroll, fade, dissolve, fly -in and animated images.
The additional transitions allow for multiple screens of information on a subject to be
displayed at `medium' speed setting before pausing two (2) seconds prior to presenting a
new message subject.
Feedback from residents, business owners, dignitaries, and city staff, including the Police
and Parks Departments, has been randomly solicited regarding the effectiveness of these
transitioning methods, length, hold times, transition times, and usefulness of fresh
information.
Based on verbal feedback, the following examples were noted:
Message content that transitioned without a long pause stimulated more
Public Hearings 502 PAGE 3 OF 6 - July 28, 2014
interest.
Fresh messages were welcomed while messages left in rotation for thirty (30)
days or more almost completely lost viewer interest.
Due to the flexibility of additional transitions, more detailed information on
each subject was provided, which increased interest and retention.
The EMC was more appealing and "ALIVE! ", as described by one resident.
No negative feedback was noted regarding the EMC during the evaluation
period.
The City's Police and Parks Departments commented on several occasions
about how much more useful the sign has become in getting important
information out to the community.
In conclusion, the transition methods utilized during our ninety (90) day evaluation period
have greatly increased the utility of the EMC at City Hall by allowing for more pertinent
and visually stimulating information to reach our mobile audiences. Based on results of this
evaluation and various publicized scientific studies, it is reasonable to assume that
Ordinance 2014 -13 would be beneficial to the city's economical development initiatives
and serve to enhance the public benefit of all EMC's within the city. Businesses who operate
an EMC will have a low cost venue for broadcasting larger volumes of relevant information
to consumers, thereby increasing opportunities to stimulate sales within the local tax base.
SUPPORTING INFORMATION
SAFETY
In a 2001 publication by the U.S. Small Business Administration (SBA) on Electronic
Message Centers, the Federal Government has made the determination that EMC's are not a
distraction to roadway drivers, in fact they were found to generally increase driver safety
when configured properly. The publication cited a Federal Highway Administration
Commissioned Study completed in 1980 which set out to prove that Electronic Variable
Message Centers were unsafe for drivers. After extensive research, the study concluded that
no credible statistical evidence was available to support a conclusion that electronic or
variable message centers negatively impacted road safety. The writer of the report opined
that roadside signs, in general, provided a stimulus that helped to maintain driver alertness
and increase safety by combating driver fatigue.
Moreover, the SBA published information showing several states that have conducted
safety studies on the affects of roadside signs, including EMC's, and none have found an
increase in roadside accidents. In fact, some states found a significant decrease in accidents,
which is attributed directly to the roadway signs. In addition, as part of the SBA
Publication, nine leading insurance companies were surveyed about accidents related to
roadway signage and all companies indicated that they had never received an accident claim
involving an advertising sign.
On December 27, 2013, the U.S. Department of Transportation Federal Highway
Administration (FHWA) released a multi -year study on driver visual behavior in the
presence of Changeable Electronic Variable Message Signs that stated, "The present data
suggest that the drivers in this study directed the majority of their visual attention to areas
of the roadway that were relevant to the task at hand (e.g., the driving task). " Furthermore,
it is possible, and likely, that in the time that the drivers looked away from the forward
roadway, they may have elected to glance at other objects in the surrounding environment
(in the absence of billboards) that were not relevant to the driving task. "When billboards
Public Hearings 502 PAGE 4 OF 6 - July 28, 2014
were present, the drivers in this study sometimes looked at them, but not such that overall
attention to the forward roadway decreased. "
According to the abovementioned 2001 SBA Publication, "the electronic message display
rapidly becomes a landmark in a business's local community, because it offers a valuable
public service to the entire community by displaying public service information, civic
events, personal and holiday greetings, current time and temperature and specific
advertising messages." The report further stated, "Passing viewers often look forward to
reading clever new messages, and may even come to rely upon the message service in some
settings. But, most importantly to the business owner, the passing viewers will remember
what the business is, and where the business is located."
A recent study conducted by the Virginia Tech Traffic Institute (VTTI) concluded the
average amount of time it takes for a driver of a car to look at an electronic message display
and read and process the information is approximately 1 second during a 6 second period.
This study concluded that traffic accidents are no more likely to occur in the presence of
electronic message displays than in their absence. An additional study by VTTI concluded
texting while driving causes a driver to glance at their respective mobile device for an
average of 4.6 seconds during a 6 second period. This equates to a driver traveling then
length of a football field at 55 miles per hour without looking at the roadway. A 2 second
glance away from the road is considered to be a dangerous level.
FISCAL IMPACT:
While there is no direct fiscal impact to the City, staff is of the opinion that the proposed
new code language will facilitate more diversified development and increase the chance of
local businesses remaining viable over the long term, which will have a positive fiscal
impact to the City's tax base.
COMMUNICATION EFFORTS:
This Agenda Item has been electronically forwarded to the Mayor and City Commission,
City Manager, City Attorney /Staff, and is available on the City's Website, LaserFiche, and
the City's Server. Additionally, portions of this Agenda Item are typed verbatim on the
respective Meeting Agenda which has also been electronically forwarded to the individuals
noted above, and which is also available on the City's Website, LaserFiche, and the City's
Server; has been sent to applicable City Staff, Media/Press Representatives who have
requested Agendas /Agenda Item information, Homeowner's Associations/Representatives
on file with the City, and all individuals who have requested such information. This
information has also been posted outside City Hall, posted inside City Hall with additional
copies available for the General Public, and posted at five (5) different locations around the
City. Furthermore, this information is also available to any individual requestors. City Staff
is always willing to discuss this Agenda Item or any Agenda Item with any interested
individuals.
This item was advertised in the Orlando Sentinel on June 12, 2014.
RECOMMENDATION:
Staff recommends the City Commission approve Ordinance 2014 -13, which proposes to
amend the City's regulations regarding off - premises signs, commonly referred to as
Public Hearings 502 PAGE 5 OF 6 - July 28, 2014
billboards, and electronic message centers.
ATTACHMENTS:
A. Ordinance 2014 -13
B. Ordinance 2013 -11 - provided for technical display requirements
C. SBA Publication on EMC's (200 1)
D. FHA Study CEVMS (Sept. 2012)
E. Minutes, Planning & Zoning Board - June 4, 2014
F. Advertisement, Orlando Sentinel - June 12, 2014
Public Hearings 502 PAGE 6 OF 6 - July 28, 2014
Attachment "A"
ORDINANCE NO. 2014 -13
AN ORDINANCE OF THE CITY COMMISSION OF THE CITY OF
WINTER SPRINGS, SEMINOLE COUNTY, FLORIDA, REGARDING
THE REGULATION OF EXISTING OUTDOOR OFF - PREMISE
ADVERTISING DISPLAYS /BILLBOARDS LOCATED WITHIN THE
CITY OF WINTER SPRINGS ON U.S. 17 -92; AMENDING THE CODE
RELATED TO CHANGEABLE COPY SIGNS AND ELECTRONIC
MESSAGE CENTERS; PROVIDING FOR THE REPEAL OF PRIOR
INCONSISTENT ORDINANCES AND RESOLUTIONS,
SEVERABILITY, INCORPORATION INTO THE CODE; AND AN
EFFECTIVE DATE.
WHEREAS, the City is granted the authority, under § 2(b), Art. VIII of the State Constitution, to
exercise any power for municipal purposes, except when expressly prohibited by law; and
WHEREAS, the City has previously adopted regulations regulating outdoor off - premises
advertising displaysibillboards and changeable copy signs and electronic message centers within the
municipal limits of the City; and
WHEREAS, based upon previous legislative findings and upon recommendation of the City's
Community Development Department, the City Commission desires to modify several technical provisions
of the City's existing billboard sign regulations;
WHEREAS, the City's Land Planning Agency conducted a public hearing regarding the Code
amendments recommended by the Community Development Department set forth in this Ordinance on
June 4, 2014, and recommended that the City Commission adopt the amendments; and
WHEREAS, the City Commission of the City of Winter Springs, Florida, hereby finds this
ordinance to be in the best interests of the public health, safety, and welfare of the citizens of Winter
Springs.
NOW, THEREFORE, THE CITY COMMISSION OF THE CITY OF WINTER SPRINGS
HEREBY ORDAINS, AS FOLLOWS:
Section 1. Recitals. The foregoing recitals are hereby fully incorporated herein by reference
as legislative findings of the City Commission of Winter Springs.
Section 2. Chapter 16 Sign Code Amendment. The City of Winter Springs Code of
Ordinances, Chapter 16, Article III, Signs, is hereby amended as follows (underlined type indicates
additions and str-ikeet4 type indicates deletions, while asterisks (* * *) indicate a deletion from the
Ordinance of text existing in Chapter 16, Article III. It is intended that the text in Chapter 16, Article III,
denoted by the asterisks and set forth in this Ordinance shall remain unchanged from the language existing
prior to adoption of this ordinance).
City of Winter Springs
Ordinance No. 2014 -13
Sec. 16 -77. - Outdoor display /billboards— Off - premises signs prohibited.
(k) This subsection is intended to provide requirements for a person to propose converting an
existing structure identified on the aforementioned inventory list, and which is located on real property
abutting U.S. 17 -92 and within the Seminole County 17 -92 Redevelopment Area, to an off - premises digital
billboard sign under negotiated terms and conditions approved by the City Commission. The purpose of
this subsection is to adopt standards and restrictions for any such conversion that are pursuant to the interest
of the citizens of the City and Seminole County and the Redevelopment Area related to visual aesthetics
and the safety of vehicular traffic. No conversion shall be allowed in the City except as provided in this
subsection.
(2) If the City desires to engage in formal negotiations, the owner shall be required, as a
precondition to negotiations, to execute an affidavit on a form prepared by the City Attorney. The affidavit
shall provide at a minimum that the owner is acknowledging and agreeing that the future negotiations with
the City are optional and at the sole discretion of the City. Further, the owner agrees that the City is under no
obligation whatsoever to approve or deny the request and that the owner shall release and hold harmless the
City regarding any decision made by the City on the request. Should the City Commission decide to
approve an owner's conversion proposal, the conversion shall be subject to terms and conditions of a
binding written agreement and the following minimum standards and requirements:
(vi) Notwithstanding the current location of the existing structure being removed pursuant to
this subsection, the City may require the digital billboard to be located elsewhere on the subject property in
order to provide adequate buffer distances from the digital billboard and U.S. 17 -92 and other public
right -of -way, as well as from other sensitive areas adjacent to the subject property, or require the billboard
to be located on other property abutting U.S. 17 -92 which is owned by the owner of the structure or subject
property if the relocation of the structure more fully satisfies the purpose of subsection (k) in comparison to
the property on which the structure currently. ems;
Sec. 16 -81- Changeable copy signs; electronic message centers.
All changeable copy signs and electronic message centers shall be as follows:
(b) Changeable copy signs and electronic message centers may be incorporated into permitted
signs and shall be included as part of the permitted sign area as described below:
City of Winter Springs
Ordinance No. 2014 -13
2
(1) With the exception of billboards which are regulated by other provisions of the City Code,
changeable copy signs shall not comprise more than twenty -five (25) percent of the permitted sign area and
electronic message centers shall not comprise more than fifty (50) percent of the permitted sign area.
(2) Electronic message centers shall display J c g ea! ,,. StiEh stuticimag€s sha4tea
messages
using the following transitional methods only: static, fade, dissolve, scroll, and fly -in. Static messages
shall hold the display face for a minimum of two (2) seconds before transitioning to another static image.
Messages that fade, dissolve, scroll, and fly -in shall transition to and from the display area at a rate of speed
no faster than the medium speed program setting.
(3) Messages or images displayed shall not have the appearance of flashing, flickering
blinking, pulsating, or motion videos. -rFansitions from e stat ,. image to the a&4 shall , e r ithil
Section 5. Repeal of Prior Inconsistent Ordinances and Resolutions. All prior
inconsistent ordinances and resolutions adopted by the City Commission, or parts of prior ordinances and
resolutions in conflict herewith, are hereby repealed to the extent of the conflict.
Section 6. Incorporation Into Code. This Ordinance shall be incorporated into the Winter
Springs City Code and any section or paragraph, number or letter, and any heading may be changed or
modified as necessary to effectuate the foregoing. Grammatical, typographical, and like errors may be
corrected and additions, alterations, and omissions, not affecting the construction or meaning of this
Ordinance and the City Code may be freely made.
Section 7. Severability. If any section, subsection, sentence, clause, phrase, word or
provision of this ordinance is for any reason held invalid or unconstitutional by any court of competent
jurisdiction, whether for substantive, procedural, or any other reason, such portion shall be deemed a
separate, distinct and independent provision, and such holding shall not affect the validity of the remaining
portions of this ordinance.
Section 8. Effective Date. This Ordinance shall become effective immediately upon
adoption by the City Commission of the City of Winter Springs, Florida, and pursuant to the City Charter.
City of Winter Springs
Ordinance No. 2014 -13
ADOPTED by the City Commission of the City of Winter Springs, Florida, in a regular meeting
assembled on the day of 12014.
CHARLES LACEY, Mayor
ATTEST:
ANDREA LORENZO - LUACES
City Clerk
APPROVED AS TO LEGAL FORM AND SUFFICIENCY
FOR THE CITY OF WINTER SPRINGS ONLY.
ANTHONY A. GARGANESE
City Attorney
First Reading:
Legal Ad Published:
Effective Date:
City of Winter Springs
Ordinance No. 2014 -13
4
Attachment "B"
ORDINANCE NO. 2013-11
AN ORDINANCE OF THE CITY COMMISSION OF THE CITY
OF WINTER SPRINGS, SEMINOLE COUNTY, FLORIDA,
REGARDING THE REGULATION OF EXISTING OUTDOOR
OFF - PREMISE ADVERTISING DISPLAYS /BILLBOARDS
( "BILLBOARDS ") LOCATED WITHIN THE CITY OF WINTER
SPRINGS ON U.S. 17 -92; PROVIDING REQUIREMENTS FOR
CONVERTING EXISTING, LEGALLY NONCONFORMING
BILLBOARDS LOCATED ON U.S 17 -92 INTO DIGITAL
BILLBOARDS PURSUANT TO SUBSEQUENTLY
NEGOTIATED TERMS AND CONDITIONS OF AN
AGREEMENT WITH THE CITY; PROVIDING FOR THE
REPEAL OF PRIOR INCONSISTENT ORDINANCES AND
RESOLUTIONS, SEVERABILITY, INCORPORATION INTO
THE CODE; AND AN EFFECTIVE DATE.
WHEREAS, the City is granted the authority, under § 2(b), Art. VIII of the State
Constitution, to exercise any power for municipal purposes, except when expressly prohibited by
law; and
WHEREAS, the City has previously adopted regulations regulating outdoor off - premises
advertising displays /billboards ( "Billboards ") within the municipal limits of the City; and
WHEREAS, upon recommendation of the City's Community Development Department,
the City Commission desires to adopt several technical amendments to the City's existing
Billboard regulations; and
WHEREAS, the City's Land Planning Agency conducted a public hearing regarding the
Code amendments recommended by the Community Development Department set forth in this
Ordinance on September 4, 2013 and recommended that the City Commission adopt the
amendments; and
WHEREAS, the City Commission hereby adopts by this reference for the sake of
simplicity, all previous legislative findings and references to legal authority made by the City
Commission including, but not limited to those set forth in Ordinance 2001 -50, supporting the
regulation of Billboards within the municipal limits of the City; and
WHEREAS, the City Commission finds that U.S. 17 -92 traversing along the western
boundary of the City of Winter Springs and is the highest traffic corridor with the most intense
commercial land uses within the City; and
WHEREAS, given the character of U.S. 17 -92, the City Commission finds that affording
City of Winter Springs
Ordinance No. 2013 -11
1
the opportunity to convert an existing nonconforming billboard located within this corridor to a
digital sign may be more compatible with the corridor than the existing billboard provided certain
terms and conditions for the conversion can be negotiated with the sign and property owner.
WHEREAS, the City Commission of the City of Winter Springs, Florida, hereby finds this
ordinance to be in the best interests of the public health, safety, and welfare of the citizens of
Winter Springs.
NOW, THEREFORE, THE CITY COMMISSION OF THE CITY OF WINTER
SPRINGS HEREBY ORDAINS, AS FOLLOWS:
Section 1. Recitals. The foregoing recitals are hereby fully incorporated herein by
reference as legislative findings of the City Commission of Winter Springs.
Section 2. Amendment to Section 16 -77 of the City Code. The City of Winter
Springs Code of Ordinances, Section 16 -77 is hereby amended as follows (underlined type
indicates additions and strrikeet4 type indicates deletions, while asterisks (* * *) indicate a deletion
from the Ordinance of text existing in Section 16 -77.
Sec. 16 -77. - Outdoor display /billboards— Off - premises signs prohibited.
(a) Other than as provided within this section, off - premises signs, as defined in section
16 -51 of the City Code, are strictly prohibited within the City of Winter Springs.
(b) Notwithstanding anything in the City of Winter Springs Code of Ordinances to the
contrary, from and after the effective date of Ord. No. 2001 -50 [Oct. 22, 2001], the total number of
outdoor off - premises signs located in the incorporated areas of the city shall be limited as hereafter
specified.
(c) The initial limitation on outdoor off - premises signs are the five (5) outdoor
off - premises sign structures (hereinafter referred to as "Existing Structure(s) ") currently existing
in the incorporated areas of the city (the "Existing Structures "). An inventory of these existing
structures dated October 22, 2001, as amended in June 2013, is filed in the community
development department and is incorporated herein by this reference.
(d) The limit stated in subsection (c) above may only be increased by the number of
lawfully existing off - premise sign structures within unincorporated areas of Seminole County
which are annexed by the City of Winter Springs. Contemporaneously with annexation the city
shall conduct a survey of all existing off - premise sign structures within the annexed portions of
unincorporated Seminole County. The inventory of existing structures, on file with the community
development department, shall be amended by resolution of the city commission to include the
addition of legally existing off - premise sign structures.
City of Winter Springs
Ordinance No. 2013 -11
(e) The limit stated in subsection (c) above, as may be amended by subsection (d), shall
be correspondingly reduced upon the occurrence of any of the following:
(1) An existing structure is removed incident to a road widening or other public works
project; and
(2) An existing structure is removed incident to the development or redevelopment of the
property upon which the existing structure is located; or
(3) An existing structure is removed incident to the expiration of the lease or other
agreement authorizing placement of the existing structure on the property.
(4) An existing structure which is non - conforming due to zoning is removed due to
destruction, damage or other casualty which results in destruction of fifty (50) percent or more of
the support structure for or of fifty (50) percent or more of the face of the sign.
(5) An existing structure is removed or dismantled by fifty (50) percent or more of the
support structure or fifty (50) percent or more of the face of the sign.
(6) By the terms and conditions of a development agreement with the city, except that any
development agreement after the effective date of this section shall not allow the removal of an
existing structure later than the time that would otherwise be provided by this section. Any existing
structure subject to a development agreement with the city prior to the effective date to this section
shall be exempt from the provisions of this subsection (e) and shall be removed in accordance with
the terms of the development agreement.
(f) At any point in time the then current limit on the number of outdoor off - premises signs
located in the incorporated areas of the city shall be the initial limit specified in subsection (c) and
as amended by subsection (d) above less the total number of existing structures which have been
removed as specified in subsection (e) above.
(g) In addition to the limitation specified above, there is hereby imposed a limitation upon
the number, size and orientation of the sign faces located upon the existing structures. From and
after the effective date of Ord. No. 2001 -50 [Oct. 22, 2001], the number of sign faces on an
existing structure may not be increased, either by adding an additional face oriented in a different
direction or by changing the display mechanism to permit the display of multiple signs on a single
sign face. From and after the effective date of this Ord. No. 2001 -50, no sign face on an existing
structure may be increased in size and the orientation of each sign face located upon an existing
structure may not be changed.
(h) Except for an existing structure which is non - conforming (which cannot be replaced),
an existing structure damaged or destroyed by flood, fire, earthquake, war, riot, act of God or other
similar casualty loss may be reconstructed in the same location with the same (or smaller or fewer,
City of Winter Springs
Ordinance No. 2013 -11
as the case may be) size and number of sign faces. An existing structure may not be relocated to
another location.
(i) Except as specifically authorized by permit issued by the State of Florida Department
of Transportation or as required by specific state statute, no trees or vegetation shall be removed or
trimmed from the property upon which an outdoor off - premises sign is located or from property
adjacent thereto in order to enhance the visibility of the outdoor off - premises sign.
0) In connection with any off - premise signs which are erected or constructed in violation
of the provisions of this section, each day that said sign remains erected in violation of this section
shall constitute a separate violation and each person responsible for erecting or constructing such
off - premise sign, including but not limited to the real property owner, shall pay the city a penalty
of five hundred dollars ($500.00) per day until the off - premise sign is removed.
(k) This subsection is intended to provide requirements for a person to propose
converting an existing structure identified on the aforementioned inventory list, and which is
located on real property abutting U.S. 17 -92 and within the Seminole County 17 -92
Redevelopment Area, to an off - premises digital billboard sign under negotiated terms and
conditions approved by the City Commission. The purpose of this subsection is to adopt
standards and restrictions for any such conversion that are pursuant to the interest of the citizens of
the City and Seminole County and the Redevelopment Area related to visual aesthetics and the
safety of vehicular traffic. No conversion shall be allowed in the City except as provided in this
subsection.
(1) An owner of an existing structure subject to this subsection shall first be required to
submit, in writing, a conversion request to the City for an informal and preliminary review to
determine whether the City, at its discretion, desires to engage in more formal negotiations
regarding the he request.
(2) If the City desires to engage in formal negotiations, the owner shall be required, as a
precondition to negotiations, to execute an affidavit on a form prepared by the City Attorney
affidavit shall provide at a minimum that the owner is acknowledging and nd a reeing that the future
negotiations with the City are optional and at the sole discretion of the City. Further, the owner
agrees that the City is under no obligation whatsoever to approve or deny the request and that the
owner shall release and hold harmless the Citesregarding any decision made by the City on the
request. Should the City Commission decide to approve an owner's conversion proposal the
conversion shall be subject to terms and conditions of a binding written agreement and the
following minimum standards and requirements:
(i) if the owner of the existing structure is not the owner of the property on which the
existing structure is located, the owner of the property shall be required to approve and execute the
agreement. Said agreement shall be recorded in the Official Records of Seminole County and
shall be binding on the owner of the sign and the real property,
City of Winter Springs
Ordinance No. 2013 -11
4
(ii) the conversion shall be subject to all applicable building, fire and land development
codes and law; however, to the extent this section conflicts with state or federal law, the more
restrictive will be applied by the City,
(iii) the following minimum technical display requirements shall apply unless the City
Commission requires more restrictive requirements by written agreement:
1. Display messages shall be static only. Such static images shall hold the display face
for a minimum of eight (88) seconds before transitioning to another static image.
2. Transitions from one static image to the next shall appear within three (3) seconds
and shall not have the appearance of flashing, flickering, blinking, pulsating animation
or videos or varying light intensity. Dissolving from one static image to the next within
the three (3) second transition period shall not constitute animation for purposes of this
article.
3. The billboard shall come equipped with functioning automatic dimming
technology which automatically adjusts, at all times while the electronic message center
is operating, the he si ng s brightness in direct correlation with ambient light conditions.
4. No billboard shall be brighter than is necessary for clear and adequate visibility.
No electronic billboard shall exceed a brightness level of 6,000 NITS (NITs are the
standard measure of brightness for electronic signs and devices) during daytime use or
500 NITs during nighttime use and to account for adverse weather conditions that
reduce the amount of sunlight.
5. No billboard shall display light of such intensity or brilliance as to cause lam
otherwise impair the vision of a driver or result in a nuisance. No billboard shall be of
such intensitv or brilliance that it interferes with the effectiveness of an official traffic
sign, device or signal.
6. The billboard shall have a default mechanism built in to either turn the display off
or show "full black" on the display in the event of a malfunction. Malfunction is defined
as any operation of the billboard that causes glare or impairs the vision of motorists or
otherwise distracts motorists so as to interfere with the motorists' ability to safely
operate their vehicles or otherwise constitutes a violation of the Cites
7. The billboard shall not be configured to resemble a warning danger signal, official
signage used to control traffic or to cause a driver to mistake the billboard for a warning
or danger signal.
8. Any billboard operating out of compliance with any standard of this section must
City of Winter Springs
Ordinance No. 2013 -11
immediately terminate displaying an image until compliance is achieved.
(iv) The maximum height of the billboard shall be 50 -feet measured from the crown of
the adjacent U.S. 17 -92 and shall be compatible with the surrounding area;
(v) The maximum size of the billboard face, as viewed from one direction, shall be 672
square feet (14 feet by 48 feet). All visible portions of the back side of any billboard shall be
painted monochromatic black or other monochromatic, dark, neutral color, as approved by the
City. No embellishments and cut outs may be utilized on the billboard;
NO Notwithstanding the current location of the existing structure being removed
pursuant to this subsection, the City may require the digital billboard to be located elsewhere on
the subject property in order to provide adequate buffer distances from the digital billboard and
U.S. 17 -92 and other public right -of -way, as well as from other sensitive areas adjacent to the
subject property
(vii) The billboard may offer to provide copy space for public announcements like
amber and silver alerts, public emergency notices, and community events;
(viii) Upon approval by the City, the billboard shall constitute an existing structure and
shall remain on the inventory list pursuant to this section.
(ix) Section 16 -77 encourages the removal of existing structures on the inventory list
required by this section. Further, the City currently participates in the Seminole Count 1
Community Redevelopment Agency for purposes of revitalizing and redeveloping the U.S. 17 -92
corridor. In furtherance of these legitimate public purposes the City may, in its discretion and as
a condition of negotiating an agreement under this subsection, require a sign owner, in exchange
for the right to construct a digital billboard, to agree to remove another existing legally
non - conforming billboard located elsewhere in the City or within any portion of the Seminole
County 17 -92 Redevelopment Area within or outside the City's jurisdictional boundaries.
Section 5. Repeal of Prior Inconsistent Ordinances and Resolutions. All prior
inconsistent ordinances and resolutions adopted by the City Commission, or parts of prior
ordinances and resolutions in conflict herewith, are hereby repealed to the extent of the conflict.
Section 6. Incorporation Into Code. This Ordinance shall be incorporated into the
Winter Springs City Code and any section or paragraph, number or letter, and any heading may be
changed or modified as necessary to effectuate the foregoing. Grammatical, typographical, and
like errors may be corrected and additions, alterations, and omissions, not affecting the
construction or meaning of this Ordinance and the City Code may be freely made.
Section 7. Severability. If any section, subsection, sentence, clause, phrase, word or
provision of this ordinance is for any reason held invalid or unconstitutional by any court of
City of Winter Springs
Ordinance No. 2013 -11
6
competent jurisdiction, whether for substantive, procedural, or any other reason, such portion shall
be deemed a separate, distinct and independent provision, and such holding shall not affect the
validity of the remaining portions of this ordinance.
Section 8. Effective Date. This Ordinance shall become effective immediately
upon adoption by the City Commission of the City of Winter Springs, Florida, and pursuant to the
City Charter.
ADOPTED by the City Commission of the City of Winter Springs, Florida, in a regular
meeting assembled on the 10th day of March, 2014.
A
ZO- LUACES
City Cleik
C ES AC
APPROVED AS TO LEGAL FORM AND SUFFICIENCY
FOR THE CITY OF WINTER SPRINGS ONLY.
ANTHONY A. GARGANESE
City Attorney
First Reading: February 24, 2014
Legal Ad Published: February 27, 2014
Effective Date: March 10, 2014
City of Winter Springs
Ordinance No. 2013 -11
7
Attachment "C"
Electronic Message Centres (EMCs)
The U-S. Small Businm Administmfion aad the
Silage Foundation for Communicafion Excellence., Inc.
Sign age for Your Business,
The US- Sin all. Business Administration and the
Signage Foundation for Commuiucation
Excellence, Inc-, have joined together to mate this
information for you, the bus mess owner.
Effective Signage is a critical component of your
retail busm'ess success, and can contribute to the
success of all businesses,
In today's very competitive business environment,
good on- premise signage is essential to helping
achieve business vitality-
M_
C copyright 20DI
SBACespoinciskup Authowaum N=ber 00-7630-43.
Electronic Message Centres (EMCs)
The U.S. Snmdl Business Administration and the
Si_wage Foundation for ComnTunication Excellenee, Inc.
50 YEARS OF SERVICE
to
America's Small Business
Tice U.S. Small Business Administration, 1953-2001
Since it'sfoundingoar July 30, 1953, the US. Small B1,ts mess Ads inistration has delivered ab-owt 20
million loans, loan guarantees, contracts, counselling sessions and otherforwis of assistance to small
husinesses.
Mission
Maintain and strengthen the nation's economy y aiding, Ing
my counselling, assist and protect' the
interests of small businesses and by helping families and finesses recover from national disasters.
more Information About SBA
And the content ftom this paper may be found on the United States Small Business Administrative Web
Site.
www.SBA.jao
http - //`w-ww.,,.-,b a. Zt�v/st ar tin al s I anage-Ite Aleme. huni
0 COp3Ti& 2001
page2ofll SBA Cospomm-Jup Audionzatm Numbef 00-763"3-
Electronic Message Centres (EMCs)
-Me U.S. small Business Administration and the
siege Foundation for CA)mm axication Excellence, Inc.
'fable of Contents
What are EMCs? 4
Feah. s and Advantages of EMCs 4
Frequently Asked Questions 5
How are message centres used`? 5
Why does my business need a -message centre? 5
How wtu are EMC work best for may business? 6
Is an EMC a cost-effective advertising tedi -Lun? C
What level of rett i on investment can I expect? 7
How -much can I expect to spend on an electronic message centre? 7
What about safety? 8
Electronic Message Centres: Safe and Legal 9 -11
Notes I I
er O ce 2001
Page 3 sRA Co m-AT Authonzauon Number 00-763 3_
Electronic Message Centres (EMCs)
The U.S. Sni-Al Business Administmti<m and the
Signage Foun&fim for Conum=cafion Excellence, Inc,
What are .EMCs?
Electronic variable message centres are computerized programmable electronic Vislial communication devices.
They axe capable of staring and displaymg multiple messages in dozens of formals and at varymg intervals.
Sirnilar to reader boards, they allow their owners to change copy frequently, but. without the cost of replacing
missing or broken letters'. and without the physical labour involved in changing copy-
An Answer to the Chatlenge of Changing Demographics
The public — your existing and potential customers — is on the move, both literally and figuratively, and
sometimes catching their attention is like hitting a moving target. Consider that approximately 18.60No of
Americans move every year. Whether they move a short or long distance, they usually change their basic trade
area.. Add to that the fact that 15-35% of the traffic on a given street is Just passing through" (vacation travellers
and such). and you can see the great potential for single stops by those mifhamb ar with the area.
An electronic or variable message centre offers a unique way to capture the attention of these passers -by. An
EMC allows you to communicate more effectively with the typical person passing by at a particular time of day
by chakging the message and graphic of your sign to match the profile on the street.
This kind of flexibility increases the readership of a message unit, as it can correspond to the traffic profile by the
day of the week, the time of day, or the season. With the right software, virtually any message can be created and
displayed.
The demand by businesses for these electronic or variable message centers is increasing because these signs
improve the econolmic viability of difficult commercial. sites with limited space. Municipalities drat. wish to
prevent urban sprawl of deterioration of -urban land are passing enabling act-, that require optimizati(m of urban
space, and thus are more wfflmg to look at EMCs as a signage option for businesses.
Features and Advantages of EIMCs
• Uphinited number of message changes and variable controls result in lower labour cost and elimination of
the physical liabilities often associated with copy changes on traditional reader boards-
• Variable Messages as people pass by in Umn
� , allowing greater flexibility . co unicating to fire piNic.
• Flexibility m=s your business can advertise specials while also displaying public service information Of
other item of public interest
• These signs can. quickly brand7 your business site in the local community.
• Investment in your business and provide the best and most cost-effective forms of paid advertising. The
only form of advertising that may be more powerful is word of mouth.
• Effectiveness of an EMC not limited by space or surface area constraints as with a reader-board.
• EMCs act as your "salesman on the street," attracting new customers to your business location.
• Allows you to market your products and services to your immediate trade area and prevent wasteful
advertising expenses.
• Business owners can change the message as needed to provide information to specific retail customers, and
can be used for political, social or corturianity events-
• Software is available that enables business owners to display sophisticated logos or images on the EMC
precisely as planned.
Iii summary_ Although they may require a greater initial investment. clectronic message centres offer many
different advantages for the business owner to consider.
C copyright 2001
Page 4 of I I S13A CmTausurdW Authomaum Nimober 00-7630-43-
Electronic Mmage Centres (EMCs)
The U.S. Smalt Businm Administration and the
Signage Foundation for Comnninication Excellence, inc-
Fre- quently Asked Questions
Haw are nmssrage centres used?
Message centres are used by businesses that want the flexibility to control their own graphics and message built
and be able to change their communication to meet their needs and the needs of their customers.
• Large Corporations — have used such devices for years, in fonuns .ranging from smarts stadia to Tunes
Square. They like the ability to advertise their products in a dynamic format in which they can change
their messages frequently and easily-
• State Highway Departments have also realized the value of electronic message centres, and are
incrreasin4y using them to inftann and direct traffic in large metropolitan areas, thereby using traffic
congestion and increasing traffic safety. Large - scale urban studies are currently being done to expand
message centre use in this area, with other °`intelligent" components, to create integrated intelligent
transportation systems. Under the Manual can Uniform Traffic Control Devices (MUTCD)_ they are used
for regulatory, warning, and guidance purposes related to traffic control.
• Local Banks have for years used the familim time and temperature units.
• Ski Businesses are quickly realizing the advertising power of these dynamo visual communications
devices as most people in the community look at the signs frequently. Although EMC's have been quite
expeusive in the past., often costing around 30,000(USD) or more for a sing 1, simple unit, recent
technological breakthroughs have drastically reduced production and operating casts, brining them within
an affordable range.
• Entertainment establishments, restaurants, casinos:, and theme parts use FNICs extensively to create a
district or zone effect.
We have a sign; Iv y does my business need a message c- entre?
Consider for a moment the speed at which traffic passes by the average business. A motorist has only a few
seconds to see and comprehend any given sign. For example, on a street with traffic passing at 45 miles per hour,
a car that is 500 feet in front of a given sign will have only 7.6 seconds to read the sign before it passes, under
normal driving conditions_ A business' sign must be conspicuous if it is to catch the limited amount of time
available.
Motorists often spot electronic message centres quickly because the copy changes, the letters are illuminated, and
the signs have traditionally been used as public service devices. AddirtioDally. electronic message centres stray
have a greater visibility from fluther• distances, especially in poor lighting conditions, giving the motorist
additional time to read the message displayed while safely nianueuvring his or her vehicle.
Message Centres act as a consolidating tyke of advertising- In other words, they offer businesses .a, way of posting
a variety of information in one place rather then relying on numerous signs and banners displayed in windows, for
example. This can be a real advantage fear a business located in a district with strict rules about terrlporar-y signs.
Most importantly, the electronic incssage centre alinost always increases a business's slwe of revenue. This is a
result of the "branding" of the site through the Ilse of specific logos, reinforcement of tither advertising messages,
allowing for public service notices, generating exact impulse stops, and helping to change customers' buying
habits once they have stopped.
Page 5 of r r 0 copyright 2001
SBA Caspam ship Auflw"z�ti� Number o(1- 763E -43_
Electronic Message Centres (EMCs)
The U.S. Small Business Administration and the
Signage Foimdafion for Communication Excellence, hie.
Frequently Asked Questions
Hcnv will art electronic message displqy quark best or nq buyine-vs'
The growth in munber of media options in recent years is good news for businesses because of the variety
available to meet individual business coinitimication needs. However, each new advertising option draws, its
audience away from other existing audiences. This is not true with EMCs. The display's audience is determined
by the signs message, its location, and the inimber of vehicles that pass it each day, and its audience coutitinally
grows.
The electronic message display rapidly becomes a landmark in a business's local corm musrity, because it offers a
valuable public service to the entire comTmmity by displaying:
• Public set-vice information
• civic events
• Personal and holiday greetings
• Ctrent time and temperature
• Specific advertising messages
Massing viewers often look forward to reading clever new tuessages,. and may even come to rely upon die message
service in some settings. But most importantly to the business owner, the passing viewers will remember:
• What the business is, and
• Where the business is located.
Is and elearonic message centre a cost-effective advertising medium?
Yes. Businesses often select their advertising medium, and messages, based upon the cost per thousand exposures
of their message to the public. ON this basis, no other form of advertising comes close to matching the efficiency
and cost-effectiveness, dollar for dollar, of an electronic message display. Compare the figures below:
• Newspaper advertising - the cost on average is about $7.39 for 1000 exposures within a 10 mile radius of
the business location.
• Television advertising - The cost on average is approximately $45,26 per 1000 exposures.
• Radio advertising - The cost is about $5.47 per 1000 exposures.
• New LED electronic message centre display - The cost is less than $0.15 per 1000 exposures. How.?
Assume, for example, that you spend $30,000.00 on this type of system, and that its useful life is about
ten years. The amortized daily cost of the message centre would equal about $2.74. Add to this the daily
cost of electricity for this new LED unit (approximately $0,20), thus giving your business a daily message
centre expense total of S8-V-- With a daily traffic count of 20,000 vehicles passing your business, you
would have a cost of less then $0.45 per thousand exposures (counting drivers only)!
Best of all, with an electronic message centre, a business does not have to worry about missing its target almhence,
becoming "yesterday's news," of facing expensive production costs for changiiig its inessage, as happens
frequently with the other forms of advertising mentioned. with an electronic variable message display:
0 C%pyri 2001
Page 6 of I I S13A C*Wonsanlup Audwrization Nwnbct 00-7630-43-
Electronic Message Centres (ENICs)
The U.S. Small Business Administration and the
Sig age Foundation for Co anTimication Excellence, luc.
Frequently Asked Questions
What level of return on investment can I meet?
t
For businesses that eboose to enlmce their signage with an electronic message display. the owners typically see
an increase in business of 15% to I5a%, sing the smaller number, consider the following example.
A small business generating S 1,000.00 .a day in revenue adds an electronic message centre. The business soon
increases by 15 %, adding another $150 per day in total revenge. That translates hita an additional 1,050.00 a
week in revenue, or $54,600.00 per year. It has been said that in retailing, "the last dollars are the best dollars,"
meaning that each additional customer adds a ,seater marginal percentage to the business's bottom line profit In
the foregoing example, we can. only speculate upon the actual impact upon profit, but assam ng that the business
was at or above its "break- event' point before adding the electronic message centre, the addition of $54,600.00 per
year in revenue would clearly add to the bminess's profit.
Keep in mind that with this example., the investment in the electronic inessage centre unit would rely be about
one -third of the additional revenue generated in the first year of its operation alone.
How much can I expect to spend on an . electronic message centre, '
Before you wonder how much a business will spend on an electronic message centre, first determine haw tench
will be spent overall on marketing and advertising. It is not uncommon for a business that is already using a
variety of media adveitising without an electronic inessautc centre to divert some of those advertising dogs to an
investment in one of these displays, greatly increasing exposure, business volunie and customer acquisition -- all
without spending any additional revenue.
Technological breakthroughs have reduce the casts of producing these communications devices and have
d_onsiderably reduced the previous level of expense for operating message centres. New technology is available
that allows message centres to:
• Operate 24 hours a day continuously for many yeah, with .minimal. bulb or LED replacement and
• Consume electric ty at a. daily cost of as little as $020 for a small LED display, or approximately $74:.0
Per year.
Best of all, these new message cures can be purchased fear lunch less then their predecessors. Even small and
medium-sized companies are fu€tding an investment in a changeable el etro nic sign is worthwhile Technological
advancements ate occurring so rapidly that a g reater variety of these signs is within financial reach., differing the
small business a tremendous on -site advertising tool that ties the advertising product directly to the location where
it can be purchased.
t ar at 0 cow 2001
SBA Cosponsorship Aud izaliaa Number 00- 7530 -43_
Electronic Message Centres (EMI's)
The U.S. SmaU Business Administrafion and the
Signage Foundafion for Comnnmication Excellence, Inc.
Frequently Asked Questions
What about safety? Aren't EMO a distraction far driven?
Over the last few decades, discussion pertaining to signage has centred on four fronts:
*4 =0V
1. Maintaining the economic vitality of commercial districts through signage
2, tile First Amendment (see this SBA site's "Legal consj&rations- and the =IeZLI Resources" in the
Glossary fResources tab fbi: in-depth detail about legal rights, protections and more)
3. community aesthetics; and
4. traffic safety-
Some mi ght argue that signs cause traffic accidents by distracting the driver of a vehicle. However, this has never
been proven to he the case with a well-designed sign. A well-desi gped sign has a brief, easy-to-read message, in
letter -ag large enough to be easily seen and read by a driver. Further, the sign is illuminated to assist in its
visibility and legibility. The sign is of a sufficient size and height that it is easily smi, as well as placed in a
location where a driver would naturally look.
In anything, well-desiped and placed signage c increase safety, As quoted in the article, "I'taffic and On-
Premise Sign Regulation,'* speaks to this issue of safety in detail, "To facilitate safe. movement and meet
infbnnation needs, roadside sips, both commercial and non-commercial, must provide drivers with clear
messages that are visibrIe under all enviro mental. conditiorts. "'Ilic article colitinues wit, "Signs that do not
optimally communicate- .. can create diver frustration or disorientation-" And finally, "These driver behavioim
many times cause accidents - accidents which might have been avoided bad the pertinent sign been visible and
readable m sufficient time for the viewer/driver to process its message and safely respond.-
Electronic message centres - like oilier types of siguage - when properly designed, placed. maintained, and
illuminated can actually promote greater traffic safety.
0 Copyright 20DI
Page gofll SBA Cosponsxship Autharaxtion Number 00-7630-43-
Electronic Mr sage Centres (EM s)
The U.S. Small Business Administratim and the
Sipmgc Fomdation for Commmication ExceRence, Inc.
Electronic Message Centres. Safe and Legal
The federal government recognizes the superior communication value of ENICs and uses electronic information
panels on mmiy freeways to warn drivers of possible hazards. Its use of portable electronic warning signs at
construction or accident sites is also increasing.
possibl o the driver.. Airports ai
The sophisticated hardware that is now available makes maximum readability ef r v - s Id
highway departments are developing expertise in positioning and 3izkg of these signs to enable the driver to read,
react and move through traffic with optimum safety.
Electronic message centres are not a distraction to drivers. it is quite the contrary. Their exceptional readability
and couspicuity means that ElvfCs actually imitase driver safety- The federal governinent and other reviewers,
after conducting nunwrous studies, analyzing court cases, and reviewing the available literature, have concluded
that signs and electronic message centres, if used properly, are traffic safety enhancement devices.
The 1958 Federal-Aid Highway Act established federal controls for signs ilhuninated by flashing, moving or
intermittent light, The Federal-Aid. Highway 1965 Act did not contain any reference to lighting controls.
However, Federal/State agreements were entered into with all States referencing lighting restrictions on signs in
commercial or industrial areas. based on customary usage
In 1978, the Surface Transportation Assistance Act amended the highway beautification law to allow on-premise
electronic message centres along the Interstate and Federal Aid Primary road systeins, subjW to individual state
law, so long as those, signs do not contain flashing, intermittent, or moving lights. Variable message signs, whose
content can be changed or altered on a fixed display surface, are recognized by the federal government as
different from the rqMated animated signage, which fui movement or have high-intensity flashin g lights in
order to grab the viewer's attention.
Ins a 198-0 study commissioned by the Federal Highway Administration, researchers Ross Netherton and. Jerry
Wachtel set out to prove electronic variable message signs were unsafe_ They concluded, however, that no
credible statistical evidence existed to support the conclusion that electronic or variable message centres
negatively impacted road safety_ Their repoot t also said that roadside signs provided a stimulus that helped
maintain driver alertness, and increased safety by combating "highway hypnosis."
Several states have conducted studies on the safety of roadside sips, including EMCs. and Done have found an
mcreast in traffic accidents — and .in some cases found a significant decrease in accidents — related to the signs_
Fluthermore,.mine leading insum-ace companies were surveyed, and all indicated that they had never received an
accident claim involving an advertising sign,
Richard Schwab, former Federal Highway Administration program manager for research on highway visibility
and night driving safety and Fellow of the flimninating Engineering Society of North America.., conducted an
extensive study that concluded EMCs could not be linked to traffic accidents or any reduction in traffic safety.
In 1996, the Kentucky SiTreme Court struck down a state statute that prohibited signs near highways if they
contained or mcluded'llashing, ii ving. or intermittent lights except those displaying time. date., temperature or
weather." The court said the state had. failed to demonstrate that a legitimate goveniment interest was advanced by
the prohibition, and said no evidence supported the notion that so limiting the content on the display had
"anything to do with highway safety or aesthetics. -
0 copyright 2001
PW90fli S13ACv&p=ors* Audiarimton Numt-cr OD-7630 41
Electronic Message Centres (EMCs)
The U,S- Sman Business Administmfion md the
Signage Foundation for COMmimicafion Excellencv, Inc
Electronic Message Centres: Safe and Legal
It is a testament to the Safety of EMCS that since 1979, the Federal Highway Admiwisuution has not, seen my
need to revise its recognition of the legality of on-premise col-nmercial variable electronic message signage-
provided that-
I , the displays are changed at reasonable intervals,
2. the sipage does not violate tile compliance agreement's definition of flashing lights, and
3 A , uch sigas are considered to have, been in
3 , a state has accepted loc�d controls in lieu of state conti -, and s
custonmry use within the locality, or a state court has detern"ed that such. signs do not constitute
flashing, internAttent or moving lights.
'0 cWyfight 2001
Pagr 10 of I I SBAC-p--shipAulb—fix-Number (*-7630-43-
Attachment "D"
DRIVER VISUAL BEHAVIOR IN THE PRESENCE OF COMMERCIAL
ELECTRONIC VARIABLE MESSAGE SIGNS (CEVMS)
SEPTEMBER 2012
U.S. Departmentot Transportation FHWA -HEP-
Federal Highway
Administration
FOREWORD
The advent of electronic billboard technologies, in particular the digital Light- Emitting Diode
(LED) billboard, has necessitated a reevaluation of current legislation and regulation for
controlling outdoor advertising. In this case, one of the concerns is possible driver distraction. In
the context of the present report, outdoor advertising signs employing this new advertising
technology are referred to as Commercial Electronic Variable Message Signs ( CEVMS). They
are also commonly referred to as Digital Billboards and Electronic Billboards.
The present report documents the results of a study conducted to investigate the effects of
CEVMS used for outdoor advertising on driver visual behavior in a roadway driving
environment. The report consists of a brief review of the relevant published literature related to
billboards and visual distraction, the rationale for the Federal Highway Administration research
study, the methods by which the study was conducted, and the results of the study, which used an
eye tracking system to measure driver glances while driving on roadways in the presence of
CEVMS, standard billboards, and other roadside elements. The report should be of interest to
highway engineers, traffic engineers, highway safety specialists, the outdoor advertising
industry, environmental advocates, Federal policymakers, and State and local regulators of
outdoor advertising.
Monique R. Evans
Director, Office of Safety
Research and Development
Nelson Castellanos
Director, Office of Real Estate
Services
Notice
This document is disseminated under the sponsorship of the U.S. Department of Transportation
in the interest of information exchange. The U.S. Government assumes no liability for the use
of the information contained in this document. This report does not constitute a standard,
specification, or regulation.
The U.S. Government does not endorse products or manufacturers. Trademarks or
manufacturers' names appear in this report only because they are considered essential to the
objective of the document.
Quality Assurance Statement
The Federal Highway Administration (FHWA) provides high - quality information to serve
government, industry, and the public in a manner that promotes public understanding. Standards
and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its
information. The FHWA periodically reviews quality issues and adjusts its programs and
processes to ensure continuous quality improvement.
TECHNICAL DOCUMENTATION PAGE
1. Report No.
2. Government Accession No.
3. Recipient's Catalog No.
FHWA -HRT-
4. Title and Subtitle
5. Report Date
Driver Visual Behavior in the Presence of Commercial Electronic Variable
Message Signs ( CEVMS)
6. Performing Organization Code
7. Author(s)
8. Performing Organization Report No.
William A. Perez, Mary Anne Bertola, Jason F. Kennedy, and John A.
Molino
9. Performing Organization Name and Address
10. Work Unit No. (TRAIS)
SAIC
6300 Georgetown Pike
11. Contract or Grant No.
McLean, VA 22101
12. Sponsoring Agency Name and Address
13. Type of Report and Period Covered
Office of Real Estate Services
Federal Highway Administration
14. Sponsoring Agency Code
1200 New Jersey Avenue SE
Washington, DC 20590
15. Supplementary Notes
The Contracting Officer's Technical Representatives (COTR) were Christopher Monk and Thomas Granda.
16. Abstract
This study was conducted to investigate the effect of CEVMS on driver visual behavior in a roadway driving
environment. An instrumented vehicle with an eye tracking system was used. Roads containing CEVMS, standard
billboards, and control areas with no off - premise advertising were selected. Data were collected on arterials and
freeways in the day and nighttime. Field studies were conducted in two cities where the same methodology was used
but there were differences in the roadway visual environment. The gazes to the road ahead were high across the
conditions; however, the CEVMS and billboard conditions resulted in a lower probability of gazes as compared to the
control conditions (roadways not containing off - premise advertising) with the exception of arterials in Richmond where
none of the conditions differed from each other. Examination of where drivers gazed in the CEVMS and standard
billboard conditions showed that gazes away from the road ahead were not primarily to the billboards. Average and
maximum fixations to CEVMS and standard billboards were similar across all conditions. However, four long dwell
times were found (sequential and multiple fixations) that were greater than 2,000 ms. One was to a CEVMS on a
freeway in the day time, two were to the same standard billboard on a freeway once in the day and once at night; and
one was to a standard billboard on an arterial at night. In Richmond, the results showed that drivers gazed more at
CEVMS than at standard billboards at night; however, in Reading the drivers were equally likely to gaze towards
CEVMS or standard billboards in day and night. The results of the study are consistent with research and theory on the
control of gaze behavior in natural environments. The demands of the driving task tend to affect the driver's self -
regulation of gaze behavior.
17. Key Words
18. Distribution Statement
Driver visual behavior, visual environment, billboards, eye tracking
No restrictions.
system, commercial electronic variable message signs, CEVMS, visual
complexity
19. Security Classif. (of this report)
20. Security Classif. (of this page)
21. No. of Pages
22. Price
Unclassified
I Unclassified
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2514
millimeters
mm
ft
feet
0.305
meters
m
yd
yards
0.914
meters
m
mi
miles
1.61
kilometers ''
km
fl
AREA
FORCE and PRESSURE or STRESS
inZ
square inches
645.2
square millimeters
mmZ
ftZ
square feet
0.093
square meters
mZ
yd
square yard
0.836
square meters
mZ
ac
acres
0.405
hectares
ha
miZ
square miles
2.59
square kilometers
kmZ
VOLUME
fl oz
fluid ounces
29.57
milliliters
mL
gal
gallons
3.785
liters
L
ft3
cubic feet
0.028
cubic meters
m3
yd3
cubic yards
0.765
cubic meters
m3
NOTE: volumes greater than 1000 L shall
be shown in m3',!
MASS
oz
ounces
28.35
grams
g
lb
pounds
0.454
kilograms
kg
T
short tons (2000 lb)
0.907
megagrams (or "metric ton ")
Mg (or "t ")
TEMPERATURE', (exact degrees)
OF
Fahrenheit
5 (F -32)/9
Celsius
°C
or (F-32)/1.8
ILLUMINATION
fc
foot - candles
10.76
lux
Ix
fl
foot - Lamberts
3.426
candela/M2
cd /mZ
FORCE and PRESSURE or STRESS
lbf
poundforce
4.45
newtons
N
lbf /in'
poundforce per square
inch 6.89
kilopascals
kPa
APPROXIMATE CONVERSIONS FROM SI UNITS
Symbol
When You Know
Multiply By
To Find
Symbol
LENGTH
mm ''
millimeters
0.039
inches
in
m
meters ``
3.28
feet
ft
m
meters '!
1 >.09
yards
yd
km !
ss kilometers
0.621
miles
ss mi
AREA
mmZ
square millimeters
0.0016
square inches
inZ
mZ
square meters
10.764
square feet
ftZ
mZ
square meters
1.195
square yards
ydZ
ha
hectares
2.47
acres
ac
kmZ
sauare kilometers
0.386
sauare miles
miZ
MASS
g
grams
0.035 ounces
oz
kg
kilograms
2.202 pounds
lb
Mg (or "t")
megagrams (or "metric ton ") 1.103 short tons (2000 lb)
T
TEMPERATURE'S (exact' degrees)
°C
Celsius
1.8C +32 Fahrenheit
OF
ILLUMINATION
Ix
lux
0.0929 foot - candles
fc
cd /mZ
candela/M2
0.2919 foot - Lamberts
fl
FORCE and PRESSURE or STRESS
N
newtons'
0.225 poundforce
Ibf
kPa
kilopascals
0.145 poundforce per square inch
Ibf /inZ
'SI is the symbol for the International System of Units. Appropriate rounding should be made to comply with Section 4 of ASTM E380.
Revised March 2003
11
TABLE OF CONTENTS
EXECUTIVE SUMMARY
INTRODUCTION
BACKGROUND
Post -Hoc Crash Studies
Field Investigations
Laboratory Studies
Summary
STUDY APPROACH
Research Questions
EXPERIMENTAL APPROACH
EXPERIMENTAL DESIGN OVERVIEW
Site Selection
READING
METHOD
Selection of Data Collection Zone Limits
Advertising Conditions
Photometric Measurement of Signs
Visual Complexity
Participants
Procedures
DATA REDUCTION
Eye Tracking Measures
Other Measures
RESULTS
Photometric Measurements
Visual Complexity
Effects of Billboards on Gazes to the Road Ahead
Fixations to CEVMS and Standard Billboards
Comparison of Gazes to CEVMS and Standard Billboards
Observation of Driver Behavior
Level of Service
DISCUSSION OF READING RESULTS
RICHMOND
METHOD
Selection of DCZ Limits
Advertising Type
Photometric Measurement of Signs
Visual Complexity
Participants
Procedures
DATA REDUCTION
Eye Tracking Measures
iii
1
5
5
5
6
8
9
_9
12
13
14
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16
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19
20
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27
28
30
36
36
36
37
40
40
40
40
42
42
43
43
44
44
Other Measures
RESULTS
Photometric Measurement of Signs
Visual Complexity
Effects of Billboards on Gazes to the Road Ahead
Fixations to CEVMS and Standard Billboards
Comparison of Gazes to CEVMS and Standard Billboards
Observation of Driver Behavior
Level of Service
DISCUSSION OF RICHMOND RESULTS
44
44
44
45
45
47
50
51
51
51
GENERAL DISCUSSION 53
CONCLUSIONS 53
Do CEVMS attract drivers' attention away from the forward roadway and other driving
relevant stimuli? 53
Do glances to CEVMS occur that would suggest a decrease in safety? 54
Do drivers look at CEVMS more than at standard billboards? 54
SUMMARY 55
LIMITATIONS OF THE RESEARCH 55
REFERENCES
lv
57
LIST OF FIGURES
Figure 1. Eye tracking system camera placement.
Figure 2. FHWA's field research vehicle.
Figure 3. DCZ with a target CEVMS on a freeway.
Figure 4. DCZ with a target CEVMS on an arterial.
Figure 5. DCZ with a target standard billboard on a freeway.
Figure 6. DCZ with a target standard billboard on an arterial.
Figure 7. DCZ for the control condition on a freeway.
Figure 8. DCZ for the control condition on an arterial.
Figure 9. Screen capture showing static ROIs on a scene video output.
Figure 10. Mean feature congestion as a function of advertising condition and road
type (standard errors for the mean are included in the graph).
Figure 11. Distribution of fixation duration for CEVMS in the daytime and nighttime.
Figure 12. Distribution of fixation duration for standard billboards in the daytime and
13
14
17
18
18
18
19
19
23
27
30
nighttime.
31
Figure 13. Distribution of fixation duration for road ahead (i.e., top and bottom road
ahead ROIs) in the daytime and nighttime.
31
Figure 14. Heat map for the start of a DCZ for a standard billboard at night on an
arterial.
33
Figure 15. Heat map for the middle of a DCZ for a standard billboard at night on an
arterial.
33
Figure 16. Heat map near the end of a DCZ for a standard billboard at night on an
arterial.
33
Figure 17. Heat map for start of a DCZ for a standard billboard at night on a freeway.
34
Figure 18. Heat map for middle of a DCZ for a standard billboard at night on a
freeway.
34
Figure 19. Heat map near the end of a DCZ for a standard billboard at night on a
freeway.
34
Figure 20. Heat map for the start of a DCZ for a standard billboard in the daytime on
a freeway.
35
Figure 21. Heat map near the middle of a DCZ for a standard billboard in the daytime
on a freeway.
35
Figure 22. Heat map near the end of DCZ for standard billboard in the daytime on a
freeway.
35
Figure 23. Heat map at the end of DCZ for standard billboard in the daytime on a
freeway.
35
Figure 24. Example of identified salient areas in a road scene based on bottom -up
analysis.
38
Figure 25. Example of a CEVMS DCZ on a freeway.
41
Figure 26. Example of CEVMS DCZ an arterial.
41
Figure 27. Example of a standard billboard DCZ on a freeway.
41
Figure 28. Example of a standard billboard DCZ on an arterial.
42
Figure 29. Example of a control DCZ on a freeway.
42
Figure 30. Example of a control DCZ on an arterial.
42
v
Figure 31. Mean feature congestion as a function of advertising condition and road
type._
Figure 32
Figure 33
Figure 34
Figure 35
Figure 36
Figure 37
Fixation duration for CEVMS in the day and at night.
Fixation duration for standard billboards in the day and at night.
Fixation duration for the road ahead in the day and at night.
Heat map for first fixation to CEVMS with long dwell time.
Heat map for later fixations to CEVMS with long dwell time._
Heat map at end of fixations to CEVMS with long dwell time.
vi
45
47
48
48
49
50
50
LIST OF TABLES
Table 1. Distribution of CEVMS by roadway classification for various cities.
Table 2. Inventory of target billboards with relevant parameters.
Table 3. Summary of luminance (cd /m2) and contrast (Weber ratio) measurements.
Table 4. The probability of gazing at the road ahead as a function of advertising
condition and road type.
Table 5. Probability of gazing at ROIs for the three advertising conditions on arterials
and freeways.
Table 6. Level of service as a function of advertising type, road type, and time of day.
Table 7. Inventory of target billboards in Richmond with relevant parameters.
Table 8. Summary of luminance (cd /m2) and contrast (Weber ratio) measurements.
Table 9. The probability of gazing at the road ahead as a function of advertising
condition and road type.
Table 10. Probability of gazing at ROIs for the three advertising conditions on
arterials and freeways.
Table 11. Estimated level of service as a function of advertising condition, road type,
and time of day.
vii
15
17
27
28
29
37
40
44
46
46
51
LIST OF ACRONYMS AND SYMBOLS
CEVMS Commercial Electronic Variable Message Sign
EB Empirical Bayes
DCZ Data Collection Zone
ROI Region of Interest
LED Light- Emitting Diode
IR Infra -Red
CCD Charge - Coupled Device
MAPPS Multiple- Analysis of Psychophysical and Performance Signals
GEE Generalized Estimating Equations
FHWA Federal Highway Administration
DOT Department of Transportation
viii
EXECUTIVE SUMMARY
This study examines where drivers look when driving past commercial electronic variable
message signs ( CEVMS), standard billboards, or no off - premise advertising. The results and
conclusions are presented in response to the three research questions listed below:
1. Do CEVMS attract drivers' attention away from the forward roadway and other driving -
relevant stimuli?
2. Do glances to CEVMS occur that would suggest a decrease in safety?
3. Do drivers look at CEVMS more than at standard billboards?
This study follows a Federal Highway Administration (FHWA) review of the literature on the
possible distracting and safety effects of off - premise advertising and CEVMS in particular. The
review considered laboratory studies, driving simulator studies, field research vehicle studies,
and crash studies. The published literature indicated that there was no consistent evidence
showing a safety or distraction effect due to off - premise advertising. However, the review also
enumerated potential limitations in the previous research that may have resulted in the finding of
no distraction effects for off - premise advertising. The study team recommended that additional
research be conducted using instrumented vehicle research methods with eye tracking
technology.
The eyes are constantly moving and they fixate (focus on a specific object or area), perform
saccades (eye movements to change the point of fixation), and engage in pursuit movements
(track moving objects). It is during fixations that we take in detailed information about the
environment. Eye tracking allows one to determine to what degree off - premise advertising may
divert attention away from the forward roadway. A finding that areas containing CEVMS result
in significantly more gazes to the billboards at a cost of not gazing toward the forward roadway
would suggest a potential safety risk. In addition to measuring the degree to which CEVMS may
distract from the forward roadway, an eye tracking device would allow an examination of the
duration of fixations and dwell times (multiple sequential fixations) to CEVMS and standard
billboards. Previous research conducted by the National Highway Traffic Safety Administration
(NHTSA) led to the conclusion that taking your eyes off the road for 2 seconds or more presents
a safety risk. Measuring fixations and dwell times to CEVMS and standard billboards would also
allow a determination as to the degree to which these advertising signs lead to potentially unsafe
gaze behavior.
Most of the literature concerning eye gaze behavior in dynamic environments suggests that task
demands tend to override visual salience (an object that stands out because of its physical
properties) in determining attention allocation. When extended to driving, it would be expected
that visual attention will be directed toward task - relevant areas and objects (e.g., the roadway,
other vehicles, speed limit signs) and that other salient objects, such as billboards, would not
necessarily capture attention. However, driving is a somewhat automatic process and conditions
generally do not require constant, undivided attention. As a result, salient stimuli, such as
CEVMS, might capture driver attention and produce an unwanted increase in driver distraction.
The present study addresses this concern.
This study used an instrumented vehicle with an eye tracking system to measure where drivers
were looking when driving past CEVMS and standard billboards. The CEVMS and standard
billboards were measured with respect to luminance, location, size, and other relevant variables
to characterize these visual stimuli extensively. Unlike previous studies on digital billboards, the
present study examined CEVMS as deployed in two United States cities. These billboards did
not contain dynamic video or other dynamic elements, but changed content approximately every
8 to 10 seconds. The eye tracking system had nearly a 2- degree level of resolution that provided
significantly more accuracy in determining what objects the drivers were looking at compared to
an earlier naturalistic driving study. This study assessed two data collection efforts that employed
the same methodology in two cities.
In each city, the study examined eye glance behavior to four CEVMS, two on arterials and two
on freeways. There were an equal number of signs on the left and right side of the road for
arterials and freeways. The standard billboards were selected for comparison with CEVMS such
that one standard billboard environment matched as closely as possible that of each of the
CEVMS. Two control locations were selected that did not contain off - premise advertising, one
on an arterial and the other on a freeway. This resulted in 10 data collection zones in each city
that were approximately 1,000 feet in length (the distance from the start of the data collection
zone to the point that the CEVMS or standard billboard disappeared from the data collection
video).
In Reading, Pennsylvania, 14 participants drove at night and 17 drove during the day. In
Richmond, Virginia, 10 participants drove at night and 14 drove during the day. Calibration of
the eye tracking system, practice drive, and the data collection drive took approximately 2 hours
per participant to accomplish.
The following is a summary of the study results and conclusions presented in reference to the
three research questions the study aimed to address.
Do CEVMS attract drivers' attention away from the forward roadway and other driving
relevant stimuli?
• On average, the drivers in this study devoted between 73 and 85 percent of their visual
attention to the road ahead for both CEVMS and standard billboards. This range is
consistent with earlier field research studies. In the present study, the presence of
CEVMS did not appear to be related to a decrease in looking toward the road ahead.
Do glances to CEVMS occur that would suggest a decrease in safety?
The average fixation duration to CEVMS was 379 ms and to standard billboards it was
335 ms across the two cities. The average fixation durations to CEVMS and standard
billboards were similar to the average fixation duration to the road ahead.
• The longest fixation to a CEVMS was 1,335 ms and to a standard billboard it was
1,284 ms. The current widely accepted threshold for durations of glances away from the
road ahead that result in higher crash risk is 2,000 ms. This value comes from a NHTSA
4
naturalistic driving study that showed a significant increase in crash odds when glances
away from the road ahead were 2,000 ms or longer.
Four dwell times (aggregate of consecutive fixations to the same object) greater than
2,000 ms were observed across the two studies. Three were to standard billboards and
one was to a CEVMS. The long dwell time to the CEVMS occurred in the daytime to a
billboard viewable from a freeway. Review of the video data for these four long dwell
times showed that the signs were not far from the forward view while participant's gaze
dwelled on them. Therefore, the drivers still had access to information about what was in
front of them through peripheral vision.
The results did not provide evidence indicating that CEVMS, as deployed and tested in
the two selected cities, were associated with unacceptably long glances away from the
road. When dwell times longer than the currently accepted threshold of 2,000 ms
occurred, the road ahead was still in the driver's field of view. This was the case for both
CEVMS and standard billboards.
Do drivers look at CEVMS more than at standard billboards?
• When comparing the probability of a gaze at a CEVMS versus a standard billboard, the
drivers in this study were generally more likely to gaze at CEVMS than at standard
billboards. However, some variability occurred between the two locations and between
the types of roadway (arterial or freeway).
In Reading, when considering the proportion of time spent looking at billboards, the
participants looked more often at CEVMS than at standard billboards when on arterials
(63 percent to CEVMS and 37 percent to a standard billboard), whereas they looked more
often at standard billboards when on freeways (33 percent to CEVMS and 67 percent to a
standard billboard). In Richmond, the drivers looked at CEVMS more than standard
billboards no matter the type of road they were on, but as in Reading, the preference for
gazing at CEVMS was greater on arterials (68 percent to CEVMS and 32 percent to
standard billboards) than on freeways (55 percent to CEVMS and 45 percent to standard
billboards). When a gaze was to an off - premise advertising sign, the drivers were
generally more likely to gaze at a CEVMS than at a standard billboard.
In Richmond, the drivers showed a preference for gazing at CEVMS versus standard
billboards at night, but in Reading the time of day did not affect gaze behavior. In
Richmond, drivers gazed at CEVMS 71 percent and at standard billboards 29 percent at
night. On the other hand, in the day the drivers gazed at CEVMS 52 percent and at
standard billboards 48 percent.
• In Reading, the average gaze dwell time for CEVMS was 981 ms and for standard
billboards it was 1,386 ms. The difference in these average dwell times was not
statistically significant. In contrast, the average dwell times to CEVMS and standard
billboards were significantly different in Richmond (1,096 ms and 674 ms, respectively).
The present data suggest that the drivers in this study directed the majority of their visual
attention to areas of the roadway that were relevant to the task at hand (e.g., the driving task).
Furthermore, it is possible, and likely, that in the time that the drivers looked away from the
forward roadway, they may have elected to glance at other objects in the surrounding
environment (in the absence of billboards) that were not relevant to the driving task. When
billboards were present, the drivers in this study sometimes looked at them, but not such that
overall attention to the forward roadway decreased.
It also should be noted that, like other studies in the available literature, this study adds to the
knowledge base on the issues examined, but does not present definitive answers to the research
questions investigated.
M
INTRODUCTION
"The primary responsibility of the driver is to operate a motor vehicle safely. The task of driving
requires full attention and focus. Drivers should resist engaging in any activity that takes their
eyes and attention off of the road for more than a couple of seconds. In some circumstances even
a second or two can make all the difference in a driver being able to avoid a crash. " US
Department of Transportation(])
The advent of electronic billboard technologies, in particular the digital Light- Emitting Diode
(LED) billboard, has prompted a reevaluation of regulations for controlling outdoor advertising.
An attractive quality of these LED billboards, which are hereafter referred to as Commercial
Electronic Variable Message Signs ( CEVMS), is that advertisements can change almost
instantly. Furthermore, outdoor advertising companies can make these changes from a central
remote office. Of concern is whether or not CEVMS may attract drivers' attention away from the
primary task (driving) in a way that compromises safety.
The current Federal Highway Administration (FHWA) guidance recommends that CEVMS
should not change content more frequently than once every 8 seconds. (2) However, according to
Scenic America, the basis of the safety concern is that the "...distinguishing trait..." of a
CEVMS "... is that it can vary while a driver watches it, in a setting in which that variation is
likely to attract the drivers' attention away from the roadway. "(3)Thi s study was conducted to
provide the FHWA with data to determine if CEVMS capture visual attention differently than
standard off - premise advertising billboards.
BACKGROUND
A 2009 review of the literature by Molino et al. for the FHWA failed to find convincing
empirical evidence that CEVMS, as currently implemented, constitutes a safety risk greater than
that of conventional vinyl billboards. (4) A great deal of work has been focused in this area, but
the findings of these studies have been mixed .(4,5) A summary of the key past findings is
presented here, but the reader is referred to Molino et al. for a comprehensive review of studies
prior to 2008.(4)
Post -Hoc Crash Studies
Post -hoc crash studies use reviews of police traffic collision reports or statistical summaries of
such reports in an effort to understand the causes of crashes that have taken place in the vicinity
of some change to the roadside environment. In the present case, the change of concern is the
introduction of CEVMS to the roadside or the replacement of conventional billboards with
CEVMS.
The literature review conducted by Molino et al. did not find compelling evidence for a
distraction effect attributable to CEVMS .(4) The authors concluded that all post -hoc crash studies
are subject to certain weaknesses, most of which are difficult to overcome. For example, the vast
majority of crashes are never reported to police; thus, such studies are likely to underreport
crashes. Also, when crashes are caused by factors such as driver distraction or inattention, the
involved driver may be unwilling or unable to report these factors to a police investigator.
Another weakness is that police, under time pressure, are rarely able to investigate the true root
causes of crashes unless they involve serious injury, death, or extensive property damage.
Furthermore, to have confidence in the results, such studies need to collect comparable data
before and after the change, and, in the after phase, at equivalent but unaffected roadway
sections. Since crashes are infrequent events, data collection needs to span extended periods of
time both before and after introduction of the change. Few studies are able to obtain such
extensive data.
Two recent studies by Tantala and Tantala examined the relationship between the presence of
CEVMS and crash statistics in Richmond, Virginia, and Reading, Pennsylvania. (1,7) For the
Richmond area, 7 years of crash data at 10 locations with CEVMS were included in the analyses.
The study used a before -after methodology where most sites originally contained vinyl billboards
(before) that were converted to CEVMS (after). The quantity of crash data was not the same for
all locations and ranged from 1 year before /after to 3 years before /after. The study employed the
Empirical Bayes (EB) method to analyze the data.($) The results indicated that the total number
of crashes observed was consistent with what would be statistically expected with or without the
introduction of CEVMS. The analysis approach for Reading locations was much the same as for
Richmond other than there were 20 rather than 10 CEVMS and 8 years of crash statistics. The
EB method showed results for Reading that were very similar to those of Richmond.
The studies by Tantala and Tantala appear to address many of the concerns from Molino et al.
regarding the weaknesses and issues associated with crash studies. (4,6,7) For example, they
include crash comparisons for locations within multiple distances of each CEVMS to address
concerns about the visual range used in previous analyses. They used EB analysis techniques to
correct for regression -to -mean bias. Also, the EB method would better reflect crash rate changes
due to changes in average daily traffic and the interactions of these with the roadway features
that were coded in the model. The studies followed approaches that are commonly used in post -
hoc crash studies, though the results would have been strengthened by including before -after
results for non - CEVMS locations as a control group.
Field Investigations
Field investigations include unobtrusive observation, naturalistic driving studies, on -road
instrumented vehicle investigations, test track experiments, driver interviews, surveys, and
questionnaires. The following focuses on relevant studies that employed naturalistic driving and
on -road instrumented vehicle research methods.
Lee, McElheny, and Gibbons undertook an on -road instrumented vehicle study on Interstate and
local roads near Cleveland, Ohio.(9) The study looked at driver glance behavior in the vicinity of
digital billboards, conventional billboards, comparison sites (sites with buildings and other signs,
including digital signs), and control sites (those without similar signage). The results showed that
there were no differences in the overall glance patterns (percent eyes -on -road and overall number
of glances) between the different sites. Drivers also did not glance more frequently in the
direction of digital billboards than in the direction of other event types (conventional billboards,
comparison events, and baseline events) but drivers did take longer glances in the direction of
digital billboards and comparison sites than in the direction of conventional billboards and
baseline sites. However, the mean glance length toward the digital billboards was less than
on
1,000 ms. It is important to note that this study employed a video -based approach for examining
drivers' visual behavior, which has an accuracy of no better than 20 degrees.(10) While this
technique is likely to be effective in assessing gross eye movements and looks that are away
from the road ahead, it may not have sufficient resolution to discriminate what specific object the
driver is looking at outside of the vehicle.
Beij er, Smiley, and Eizenman evaluated driver glances toward four different types of roadside
advertising signs on roads in the Toronto, Canada, area.(") The four types of signs were: (a)
billboard signs with static advertisements; (b) billboard advertisements placed on vertical rollers
that could rotate to show one of three advertisements in succession; (c) scrolling text signs with a
minor active component, which usually consisted of a small strip of lights that formed words
scrolling across the screen or, in some cases, a larger area capable of displaying text but not
video; and (d) signs with video images that had a color screen capable of displaying both moving
text and moving images. The study employed an on -road instrumented vehicle with a head -
mounted eye tracking device. The researchers found no significant differences in average glance
duration or the maximum glance duration for the various sign types; however, the number of
glances was significantly lower for billboard signs than for the roller bar, scrolling text, and
video signs.
Smiley, Smahel, and Eizenman conducted a field driving study that employed an eye tracking
system that recorded drivers' eye movements as participants drove past video signs located at
three downtown intersections and along an urban expressway. (12) The study route included static
billboards and video advertising. The results of the study showed that on average 76 percent of
glances were to the road ahead. Glances at advertising, including static billboards and video
signs, constituted 1.2 percent of total glances. The mean glance durations for advertising signs
were between 500 ms and 750 ms, although there were a few glances of about 1,400 ms in
duration. Video signs were not more likely than static commercial signs to be looked at when
headways were short; in fact, the reverse was the case. Furthermore, the number of glances per
individual video sign was small, and statistically significant differences in looking behavior were
not found.
Kettwich, Kartsen, Klinger, and Lemmer conducted a field study where drivers' gaze behavior
was measured with an eye tracking system. (13) Sixteen participants drove an 11.5 mile (18.5 km)
route comprised of highways, arterial roads, main roads, and one -way streets in Karlsruhe,
Germany. The route contained advertising pillars, event posters, company logos, and video
screens. Mean gaze duration for the four types of advertising was computed for periods when the
vehicle was in motion and when it was stopped. Gaze duration while driving for all types of
advertisements was under 1,000 ms. On the other hand, while the vehicle was stopped, the mean
gaze duration for video screen advertisements was 2,750 ms. The study showed a significant
difference between gaze duration while driving and while stationary: gaze duration was affected
by the task at hand. That is, drivers tended to gaze longer while the car was stopped and there
were few driving task demands.
The previously mentioned studies estimated the duration of glances to advertising and computed
mean values of less than 1,000 ms. Klauer et al., in his analysis of the 100 -Car Naturalistic
Driving Study, concluded that glances away from the roadway for any purpose lasting more than
2,000 ms increase near - crash/crash risk by at least two times that of normal, baseline driving. (14)
7
Klauer et al. also indicated that short, brief glances away from the forward roadway for the
purpose of scanning the driving environment are safe and actually decrease near - crash /crash
risk.(14) Using devices in a vehicle that draw visual attention away from the forward roadway for
more than 2,000 ms (e.g., texting) is incompatible with safe driving. However, for external
stimuli, especially those near the roadway, the evaluation of eye glances with respect to safety is
less clear since peripheral vision would allow the driver to still have visual access to the forward
roadway.
Laboratory Studies
Laboratory investigations related to roadway safety can be classified into several categories:
driving simulations, non - driving- simulator laboratory testing, and focus groups. The review of
relevant laboratory studies by Molino et al. did not show conclusive evidence regarding the
distracting effects of CEVMS.(4) Moreover, the authors concluded that present driving simulators
do not have sufficient visual dynamic range, image resolution, and contrast ratio capability to
produce the compelling visual effect of a bright, photo - realistic LED -based CEVMS against a
natural background scene. The following is a discussion of a driving simulator study conducted
after the publication of Molino et al (4) The study focused on the effects of advertising on driver
visual behavior.
Chattington, Reed, Basacik, Flint, and Parkes conducted a driving simulator study in the United
Kingdom (UK) to evaluate the effects of static and video advertising on driver glance
behavior. (15) The researchers examined the effects of advertisement position relative to the road
(left, right, center on an overhead gantry, and in all three locations simultaneously), type of
advertisement (static or video), and exposure duration of the advertisement. (The paper does not
provide these durations in terms of time or distance. The exposure duration had to do with the
amount of time or distance that the sign would be visible to the driver.) For the advertisements
presented on the left side of the road (recall that drivers travel in the left lane in the UK), mean
glance durations for static and video advertisements were significantly longer (approximately
650 to 750 ms) when drivers experienced long advertisement exposure as opposed to medium
and short exposures. Drivers looked more at video advertisements (about 2 percent on average of
the total duration recorded) than at static advertisements (about 0.75 percent on average). In
addition, the location of the advertisements had an effect on glance behavior. When
advertisements were located in the center of the road or in all three positions simultaneously, the
glance durations were about 1,000 ms and were significantly longer than for signs placed on the
right or left side of the road. For advertisements placed on the left side of the road, there was a
significant difference in glance duration between static (about 400 ms) and video (about 800 ms).
Advertisement position also had an effect on the proportion of time that a driver spent looking at
an advertisement. The percentage of time looking at advertisements was greatest when signs
were placed in all three locations, followed by center location signs, then the left location signs,
and finally the right location signs. Drivers looked more at the video advertisements relative to
the static advertisements when they were placed in all three locations, placed on the left, and
placed on the right side of the road. The center placement did not show a significant difference in
percent of time spent looking between static and video.
Summary
The results from these key studies offer some insight into whether CEVMS pose a visual
distraction threat. However, these same studies also reveal some inconsistent findings and
potential methodological issues that are addressed in the current study. The studies conducted by
Smiley et al. showed drivers glanced forward at the roadway about 76 percent of the time in the
presence of video and dynamic signs where a few long glances of approximately 1,400 ms were
observed .(12) However, the video and dynamic signs used in these studies portray moving objects
that are not present in CEVMS as deployed in the United States. In another field study
employing eye tracking, Kettwich et al. found that gaze duration while driving for all types of
advertisements that they evaluated was less than 1,000 ms; however, when the vehicle was
stopped, mean gaze duration for advertising was as high as 2,750 ms. (16) Collectively, these
studies did not demonstrate that the advertising signs detracted from drivers' glances forward at
the roadway in a substantive manner while the vehicle was moving.
In contrast, the simulator study by Chattington et al. demonstrated that dynamic signs showing
moving video or other dynamic elements may draw attention away from the roadway. (15)
Furthermore, the location of the advertising sign on the road is an important factor in drawing
drivers' visual attention. Advertisements with moving video placed in the center of the roadway
on an overhead gantry or in all three positions (right, left, and in the center) simultaneously are
very likely to draw glances from drivers.
Finally, in a study that examined CEVMS as deployed in the United States, Lee et al. did not
show any significant effects of CEVMS on driver glance behavior.(9) However, the methodology
that was used likely did not employ sufficient sensitivity to determine at what specific object in
the environment a driver was looking.
None of these studies combined all necessary factors to address the current CEVMS situation in
the United States. Those studies that used eye tracking on real roads had animated and video -
based signs, which are not reflective of current off - premise CEVMS practice in the United
States.
STUDY APPROACH
Based on an extensive review of the literature, Molino et al. concluded that the most effective
method to use in an evaluation of the effects of CEVMS on driver visual behavior was the
instrumented field vehicle method that incorporated an eye tracking system. (4) The present study
employed such an instrumented field vehicle with an eye tracking system and examined the
degree to which CEVMS attract drivers' attention away from the forward roadway.
The following presents a brief overview and discussion of studies using eye tracking
methodology with complex visual stimuli, especially in natural environments (walking, driving,
etc.). The review by Molino et al. recommended the use of this type of technology and method;
however, a discussion laying out technical and theoretical issues underlying the use of eye
tracking methods was not presented. (4) This background is important for the interpretation of the
results of the studies conducted here.
I
Standard and digital billboards are often salient stimuli in the driving environment, which may
make them conspicuous. Cole and Hughes define attention conspicuity as the extent to which a
stimulus is sufficiently prominent in the driving environment to capture attention. Further, Cole
and Hughes state that attention conspicuity is a function of size, color, brightness, contrast
relative to surroundings, and dynamic components such as movement and change. (17) It is clear
that under certain circumstances image salience or conspicuity can provide a good explanation of
how humans orient their attention.
At any given moment a large number of stimuli reach our senses, but only a limited number of
them are selected for further processing. In general, attention can be focused on a stimulus
because it is important for achieving some goal, or because the properties of the stimulus can
attract the attention of the observer independent of their intentions (e.g., a car horn may elicit an
orienting response). When the focus of attention is goal directed, it is referred to as top -down.
When the focus of attention is principally a function of stimulus attributes, it is referred to as
bottom -up. (18)
In general, billboards (either standard or CEVMS) are not relevant to the driving task but are
presumably designed to be salient stimuli in the environment where they may draw a driver's
attention. The question is to what degree CEVMS draw a driver's attention away from driving -
relevant stimuli (e.g., road ahead, mirrors, and speedometer) and is this different from a standard
billboard? In his review of the literature Wachtel leads one to consider CEVMS as stimuli in the
environment where attention to them would be drawn in a bottom -up manner; that is, the salience
of the billboards would make them stand out relative to other stimuli in the environment and
drivers would reflexively look at these signs.(19) Wachtel's conclusions were in reference to
research by Theeuwees who employed simple letter stimulus arrays in a laboratory task. (20)
Research using simple visual stimuli in a laboratory environment are very useful for testing
different theories of perception, but often lack direct application to tasks such as driving. The
following discusses research using complex visual stimuli and tasks that are more relevant to
natural vision as experienced in the driving task.
A recent review of stimulus salience and eye guidance by Tatler et al. shows that most of the
evidence for the capture of attention by the conspicuity of stimuli comes from research in which
the stimulus is a simple visual search array or in which the target is uniquely defined by simple
visual features. (21) In other words, these are laboratory studies that use letters, arrays of letters, or
simple geometric patterns as the stimuli. Pure salience -based models are capable of predicting
eye movement endpoint in simple displays, but are less successful for more complex scenes that
contain task - relevant and task - irrelevant salient areas. (22,23)
Research by Henderson et al. using photographs of actual scenes showed that subjects looked at
non - salient scene regions containing a search target and rarely looked at salient non - task - relevant
regions of the scenes. (24) Salience of the stimulus alone was not a good predictor of where
participants looked. Additional research by Henderson using photographs of real world scenes
also showed that subjects fixated on regions of the pictures that provided task - relevant
information rather than visually salient regions with no task - relevant information. However,
Henderson acknowledges that static pictures have many shortcomings when used as surrogates
for real environments. (25�
10
Land's review of eye movements in dynamic environments concluded that the eyes are proactive
and typically seek out information required in the second before each new activity
commences. (26) Specific tasks (e.g., driving) have characteristic but flexible patterns of eye
movement that accompany them, and these patterns are similar between individuals. Land
concluded that the eyes rarely visit objects that are irrelevant to the task, and the conspicuity of
objects is less important than the objects' roles in the task. In a subsequent review of eye
movement and natural behavior, Land concluded that in a task that requires fixation on a
sequence of specific objects, the capture of gaze by irrelevant salient objects would, in general,
be an obtrusive nuisance. (22)
The literature examining gaze control under natural behavior suggests that it is principally top -
down driven, or intentional (24,2s,26,22,21,27) However, top -down processing does not explain all
gaze control or eye movements. For example, imagine driving down a two -lane country road and
a deer jumps into the road. It is most likely that you will attend and react to this deer. Unplanned
or unexpected stimuli capture our attention as we engage in complex natural tasks. Research by
Jovancevic -Misic and Hayhoe showed that human gaze patterns are sensitive to the probabilistic
nature of the environment. (28) In this study, participants' eye movement behavior was observed
while walking among other pedestrians. The other pedestrians were confederates and were either
safe, risky, or rogue pedestrians. When the study began, the risky pedestrian took a collision
course with the participant 50 percent of the time, and the rogue pedestrian always assumed a
collision course as he approached the participant, whereas the safe pedestrian never took a
collision course. Midway through the study the rogue and safe pedestrians exchanged roles but
the risky pedestrian role remained the same. The participants were not informed about the
behavior of the other pedestrians. Participants were asked to follow a circular path for several
laps and to avoid other pedestrians. The study showed that the participants modified their gaze
behavior in response to the change in the other pedestrians' behavior. Jovancevic -Misic
concluded that participants learned new priorities for gaze allocation within a few encounters and
looked both sooner and longer at potentially dangerous pedestrians. (28)
Gaze behavior in natural environments is affected by expectations that are derived through long-
term learning. Using a virtual driving environment, Shinoda et al. asked participants to look for
stop signs while driving an urban route. (29) Approximately 45 percent of the fixations fell in the
general area of intersections during the simulated drive, and participants were more likely to
detect stop signs placed near intersections than those placed in the middle of a block. Over time,
drivers have learned that stop signs are more likely to appear near intersections and, as a result,
drivers prioritize their allocation of gazes to these areas of the roadway.
The Tatler et al. review of the literature concludes that in natural vision, a consistent set of
principles underlies eye guidance. These principles include relevance or reward potential,
uncertainty about the state of the environment, and learned models of the environment. (21)
Salience of environmental stimuli alone typically does not explain most eye gaze behavior in
naturalistic environments.
In sum, most of the literature concerning eye gaze behavior in dynamic environments suggests
that task demands tend to override visual salience in determining attention allocation. When
extended to driving, it would be expected that visual attention will be directed toward task -
relevant areas and objects (e.g., the roadway, other vehicles, speed limit signs, etc.) and other
11
salient objects, such as billboards, will not necessarily capture attention. However, driving is a
somewhat automatic process and conditions generally do not require constant undivided
attention. As a result, salient stimuli, such as CEVMS, might capture driver attention and provide
an unwarranted increase in driver distraction. The present study addresses this concern.
Research Questions
The present research evaluated the effects of CEVMS on driver visual behavior under actual
roadway conditions in the daytime and at night. Roads containing CEVMS, standard billboards,
and areas not containing off - premise advertising were selected. The CEVMS and standard
billboards were measured with respect to luminance, location, size, and other relevant visual
characteristics. The present study examined CEVMS as deployed in two United States cities.
Unlike previous studies, the signs did not contain dynamic video or other dynamic elements. In
addition, the eye tracking system used in this study has approximately a 2- degree level of
resolution. This provided significantly more accuracy in determining what objects the drivers
were looking at than in previous on -road studies examining looking behavior (recall that Lee et
al. used video recordings of drivers' faces that, at best, examined gross eye movements).(9)
Two studies are reported. Each study was conducted in a different city. The two studies
employed the same methodology. The studies' primary research questions were:
1. Do CEVMS attract drivers' attention away from the forward roadway and other driving
relevant stimuli?
2. Do glances to CEVMS occur that would suggest a decrease in safety?
3. Do drivers look at CEVMS more than at standard billboards?
12
EXPERIMENTAL APPROACH
The study used a field research vehicle equipped with a non - intrusive eye tracking system. The
vehicle was a 2007 Jeep® Grand Cherokee Sport Utility Vehicle. The eye tracking system used
(SmartEye® vehicle- mounted infrared (IR) eye- movement measuring system) is shown in
figure 1.(30) The system consists of two IR light sources and three face cameras mounted on the
dashboard of the vehicle. The cameras and light sources are small in size, and are not attached to
the driver in any manner. The face cameras are synchronized to the IR light sources and are used
to determine the head position and gaze direction of the driver.
Figure 1. Eye tracking system camera placement.
As a part of this eye tracking system, the vehicle was outfitted with a three- camera panoramic
scene monitoring system for capturing the forward driving scene. The scene cameras were
mounted on the roof of the vehicle directly above the driver's head position. The three cameras
together provided an 80- degree wide by 40- degree high field of forward view. The scene
cameras captured the forward view area available to the driver through the left side of the
windshield and a portion of the right side of the windshield. The area visible to the driver
through the rightmost area of the windshield was not captured by the scene cameras.
The vehicle was also outfitted with equipment to record GPS position, vehicle speed, and vehicle
acceleration. The equipment also recorded events entered by an experimenter and synchronized
those events with the eye tracking and vehicle data. The research vehicle is pictured in figure 2.
13
Figure 2. FHWA's field research vehicle.
EXPERIMENTAL DESIGN OVERVIEW
The approach entailed the use of the instrumented vehicle in which drivers navigated routes in
cities that presented CEVMS and standard billboards as well as areas without off - premise
advertising. The participants were instructed to drive the routes as they normally would. The
drivers were not informed that the study was about outdoor advertising, but rather that it was
about examining drivers' glance behavior as they followed route guidance directions.
Site Selection
More than 40 cities were evaluated in the selection of the test sites. Locations with CEVMS
displays were identified using a variety of resources that included State department of
transportation contacts, advertising company Web sites, and a popular geographic information
system. A matrix was developed that listed the number of CEVMS in each city. For each site, the
number of CEVMS along limited access and arterial roadways was determined.
One criterion for site selection was whether the location had practical routes that pass by a
number of CEVMS as well as standard off - premise billboards and could be driven in about
30 minutes. Other considerations included access to vehicle maintenance personnel /facilities,
proximity to research facilities, and ease of participant recruitment. Two cities were selected:
Reading, and Richmond.
Table 1 presents the 16 cities that were included on the final list of potential study sites.
14
Table 1. Distribution of CEVMS by roadway classification for various cities.
State
Area
Limited Access
Arterial
Other
Total
VA
Richmond
4
7
0
11
PA
Reading
7
11
0
18
VA
Roanoke
0
11
0
11
PA
Pittsburgh
0
0
15
15
TX
San Antonio
7
2
6
15
WI
Milwaukee
14
2
0
16
AZ
Phoenix
10
6
0
16
MN
St. Paul/Minneapolis
8
5
3
16
TN
Nashville
7
10
0
17
FL
Tampa -St. Petersburg
7
11
0
18
NM
Albuquerque
0
19
1
20
PA
Scranton - Wilkes Barre
7
14
1
22
OH
Columbus
1
22
0
23
GA
Atlanta
13
11
0
24
IL
Chicago
22
2
1
25
CA
Los Angeles
3
71
4
78
(1) Other includes roadways classified as both limited access and arterial or instances where the road
classification was unknown. Source: www.lamar.com and www.clearchannel.com
In both test cities, the following independent variables were evaluated:
• The type of advertising. This included CEVMS, standard billboards, and no off - premise
advertising. (It should be noted that in areas with no off - premise advertising, it was still
possible to encounter on- premise advertising; e.g., for gas stations, restaurants, and other
miscellaneous stores and shops.)
• Time of day. This included driving in the daytime and at night.
• The functional class of roadways in which off - premise advertising signs were
located. Roads were classified as either freeway or arterial. It was observed that the
different road classes were correlated with the presence of other visual information that
could affect the driver's glance behavior. For example, the visual environment on
arterials may be more complex or cluttered than on freeways because of the close
proximity of buildings, driveways, and on- premise advertising, etc.
15
READING
The first on -road study was conducted in Reading. This study examined the type of advertising
(CEVMS, standard billboard, or no off - premise advertising), time of day (day or night) and road
type (freeway or arterial) as independent variables. Eye tracking was used to assess where
participants gazed and for how long while driving. The luminance and contrast of the advertising
signs were measured to characterize the billboards in the current study.
METHOD
Selection of Data Collection Zone Limits
Data collection zones (DCZ) were defined on the routes that participants drove where detailed
analyses of the eye tracking data were planned. The DCZ were identified that contained a
CEVMS, a standard billboard, or no off - premise advertising.
The rationale for selecting the DCZ limits took into account the geometry of the roadway (e.g.,
road curvature or obstructions that blocked view of billboards) and the capabilities of the eye
tracking system (2 degrees of resolution). At a distance of 960 ft (292.61 m), the average
billboard in Reading was 12.8 ft (3.90 m) by 36.9 ft (11.25 m) and would subtend a horizontal
visual angle of 2.20 degrees and a vertical visual angle of 0.76 degrees, and thus glances to the
billboard would just be resolvable by an eye tracking system with 2 degrees of accuracy.
Therefore 960 ft was chosen as the maximum distance from billboards at which a DCZ would
begin. If the target billboard was not visible from 960 ft (292.61 m) due to roadway geometry or
other visual obstructions, such as trees or an overpass, the DCZ was shortened to a distance that
prevented these objects from interfering with the driver's vision of the billboard. In DCZs with
target off - premise billboards, the end of the DCZ was marked when the target billboard left the
view of the scene camera. If the area contained no off - premise advertising, the end of the DCZ
was defined by a physical landmark leaving the view of the eye tracking systems' scene camera.
Table 2 shows the data collection zone limits used in this study.
Advertising Conditions
The type of advertising present in DCZs was examined as an independent variable. DCZs fell
into one of the following categories, which are listed in the second column of table 2:
• CEVMS. These were DCZs that contained one target CEVMS. Two CEVMS DCZs were
located on freeways and two were located on arterials. Figure 3 and figure 4 show
examples of CEVMS DCZs with the CEVMS highlighted in the pictures.
Standard billboard. These were DCZs that contained one target standard billboard. Two
standard billboard DCZs were located on freeways and two were located on arterials.
Figure 5 and figure 6 show examples of standard billboard DCZs; the standard billboards
are highlighted in the pictures.
16
• No off - premise advertising conditions. These DCZs contained no off - premise
advertising. One of these DCZs was on a freeway (see figure 7) and the other was on an
arterial (see figure 8).
Table 2. Inventory of target billboards with relevant parameters.
DCZ
Advertising
Type
Copy
Dimensions
(ft)
Side of
Road
Setback
.from Road
(ft)
Other
Standard
Billboards
Approach
Length (ft)
Type of
Roadway
1
CONTROL
N/A
N/A
N/A
N/A
786
Freeway
6
CONTROL
N/A
NIA
N/A
N/A
308
Arterial
3
CEVMS
10'6" x 22'9"
L
12
0
375
Arterial
5
CEVMS
14'0" x 48'0"
L
133
1
853
Freeway
9
CEVMS
10'6" x 22'9"
R
43
0
537
Arterial
10
CEVMS
14'0" x 48'0"
R
133
1
991
Freeway
2
Standard
14'0" x 48'0"
L
20
0
644
Arterial
7
Standard
14'0" x 48'0"
R
35
1
774
Freeway
8
Standard
10'6" x 22'9"
R
40
1
833
Arterial
4
Standard
14'0" x 48'0"
L
10
0
770
Freeway
*N /A indicates that there were no off-premise advertising in these areas and these values are undefined
Figure 3. DCZ with a target CEVMS on a freeway.
17
Figure 4. DCZ with a target CEVMS on an arterial.
I ..
Figure 5. DCZ with a target standard billboard on a freeway.
Figure 6. DCZ with a target standard billboard on an arterial.
IV
Figure 7. DCZ for the control condition on a freeway.
Figure 8. DCZ for the control condition on an arterial.
Photometric Measurement of Signs
Two primary metrics were used to describe the photometric characteristics of a sample of the
CEVMS and standard billboards present at each location: luminance (cd /m2) and contrast (Weber
contrast ratio).
Photometric Equipment
Luminance was measured with a Radiant Imaging ProMetric 1600 Charge - Coupled Device
(CCD) photometer with both a 50 mm and a 300 mm lenses. The CCD photometer provided a
method of capturing the luminance of an entire scene at one time.
The photometric sensors were mounted in a vehicle of similar size to the eye tracking research
vehicle. The photometer was located in the experimental vehicle as close to the driver's position
as possible and was connected to a laptop computer that stored data as the images were acquired.
Measurement Methodology
Images of the billboards were acquired using the photometer manufacturer's software. The
software provided the mean luminance of each billboard message. To prevent overexposure of
19
images in daylight, neutral density filters were manually affixed to the photometer lens and the
luminance values were scaled appropriately. Standard billboards were typically measured only
once; however, for CEVMS multiple measures were taken to account for changing content.
Photometric measurements were taken during day and night. Measurements were taken by
centering the billboard in the photometer's field of view with approximately the equivalent of the
width of the billboard on each side and the equivalent of the billboard height above and below
the sign. The areas outside of the billboards were included to enable contrast calculations.
Standard billboards were assessed at a mean distance of 284 ft (ranging from 570 ft to 43 ft). The
CEVMS were assessed at a mean distance of 479 ft (ranging from 972 ft to 220 ft). To include
the background regions of appropriate size, the close measurement distances required the use of
the 50 mm lens whereas measurements made from longer distances required the 300 mm lens. A
significant determinant of the measurement locations was the availability of accessible and safe
places from which to measure.
The Weber contrast ratio was used because it characterizes a billboard as having negative or
positive contrast when compared to its background area. (31) A negative contrast indicates the
background areas have a higher mean luminance than the target billboard. A positive contrast
indicates the target billboard has a higher mean luminance than the background. Overall, the
absolute value of a contrast ratio simply indicates a difference in luminance between an item and
its background. From a perceptual perspective luminance and contrast are directly related to the
perception of brightness. For example, two signs with equal luminance may be perceived
differently with respect to brightness because of differences in contrast.
Visual Complexity
Regan, Young, Lee and Gordon presented a taxonomic description of the various sources of
driver distraction. (32) Potential sources of distraction were discussed in terms of: things brought
into the vehicle; vehicle systems; vehicle occupants; moving objects or animals in the vehicle;
internalized activity; and external objects, events, or activities. The external objects may include
buildings, construction zones, billboards, road signs, vehicles, and so on. Focusing on the
potential for information outside the vehicle to attract (or distract) the driver's attention,
Horberry and Edquist developed a taxonomy for out -of- the - vehicle visual information. This
suggested taxonomy includes four groupings of visual information: built roadway, situational
entities, natural environment, and built environment. (33) These two taxonomies provide an
organizational structure for conducting research; however, they do not currently provide a
systematic or quantitative way of classifying the level of clutter or visual complexity present in a
visual scene.
The method proposed by Rozenholtz, Li, and Nakano provides quantitative and perhaps reliable
measures of visual clutter. (34) Their approach measures the feature congestion in a visual image.
The implementation of the feature congestion measure involves four stages: (1) compute local
feature covariance at multiple scales and compute the volume of the local covariance ellipsoid,
(2) combine clutter across scale, (3) combine clutter across feature types, and (4) pool over space
to get a single measure of clutter for each input image. The implementation that was used
employed color, orientation and luminance contrast as features. Presumably, less cluttered
20
images can be visually coded more efficiently than cluttered images. For example, visual clutter
can cause decreased recognition performance and greater difficulty in performing visual
search. (35)
Participants
In the present study participants were recruited at public libraries in the Reading area. A table
was set up so that recruiters could discuss the requirements of the experiment with candidates.
Individuals who expressed interest in participating were asked to complete a pre- screening form,
a record of informed consent, and a department of motor vehicles form consenting to release of
their driving record.
All participants were between 18 and 64 years of age and held a valid driver's license. The
driving record for each volunteer was evaluated to eliminate drivers with excessive violations.
The criteria for excluding drivers were as follows: (a) more than one violation in the preceding
year; (b) more than three recorded violations; and (c) any driving while intoxicated violation.
Forty -three individuals were recruited to participate. Of these, five did not complete the drive
because the eye tracker could not be calibrated to track their eye movements accurately. Data
from an additional seven participants were excluded as the result of equipment failures (e.g.,
loose camera). In the end, usable data was collected from 31 participants (12 males, M = 46
years; 19 females, M = 47 years). Fourteen participants drove at night and 17 drove during the
day.
Procedures
Data were collected from two participants per day (beginning at approximately 12:45 p.m. and
7:00 p.m.). Data collection began on September 18, 2009, and was completed on October 26,
2009.
Pre -Data Collection Activities
Participants were greeted by two researchers and asked to complete a fitness to drive
questionnaire. This questionnaire focused on drivers' self - reports of alertness and use of
substances that might impair driving (e.g., alcohol). All volunteers appeared fit.
Next, the participant and both researchers moved to the eye tracking calibration location and the
test vehicle. The calibration procedure took approximately 20 minutes. Calibration of the eye
tracking system entailed development of a profile for each participant. This was accomplished by
taking multiple photographs of the participant's face as they slowly rotate their head from side to
side. The saved photographs include points on the face for subsequent real -time head and eye
tracking. Marked coordinates on the face photographs were edited by the experimenter as needed
to improve the real -time face tracking. The procedure also included gaze calibration in which
participants gazed at nine points on a wall. These points had been carefully plotted on the wall
and correspond to the points in the eye tracking system's world model. Gaze calibration relates
the individual participant's gaze vectors to known points in the real world. The eye tracking
system uses two pulsating infrared sources mounted on the dashboard to create two corneal glints
that are used to calculate gaze direction vectors. The glints were captured at 60 Hz. A second set
21
of cameras (scene cameras), fixed on top of the car close to the driver's viewpoint, were used to
produce a video scene of the area ahead. The scene cameras recorded at 25 Hz. A parallax
correction algorithm compensated for the distance between the driver's viewpoint and the scene
cameras so that later processing could use the gaze vectors to show where in the forward scene
the driver was gazing.
If it was not possible to calibrate the eye tracking system to a participant, the participant was
dismissed and paid for their time. Causes of calibration failure included reflections from eye
glasses, participant height (which put their eyes outside the range of the system), and eyelids that
obscure a portion of the pupil.
Practice
After eye- tracker calibration, a short practice drive was made. Participants were shown a map of
the route and written turn -by -turn directions prior to beginning the practice drive. Throughout the
drive, verbal directions were provided by a GPS device.
During the practice drive, a researcher in the rear seat of the vehicle monitored the accuracy of
eye tracking. If the system was tracking poorly, additional calibration was performed. If the
calibration could not be improved, the participant was paid for their time and dismissed.
Data Collection
Participants drove two test routes (referred to as route A and B). Each route required 25 to 30
minutes to complete and included both freeway and arterial segments. Route A was 13 miles
long and contained 6 DCZs. Route B was 16 miles long and contained 4 DCZs. Combined,
participants drove in a total of 10 DCZs. Similar to the practice drive, participants were shown a
map of the route and written turn -by -turn directions. A GPS device provided turn -by -turn
guidance during the drive. Roughly one half of the participants drove route A first and the
remaining participants began with route B. A 5 minute break followed the completion of the first
route.
During the drives, a researcher in the front passenger seat assisted the driver when additional
route guidance was required. The researcher was also tasked with recording near misses and
driver errors if these occurred. The researcher in the rear seat monitored the performance of the
eye tracker. If the eye tracker performance became unacceptable (i.e., loss of calibration), then
the researcher in the rear asked the participant to park in a safe location so that the eye tracker
could be recalibrated. This recalibration typically took a minute or two to accomplish.
Debriefing
After driving both routes, the participants provided comments regarding their drives. The
comments were in reference to the use of a navigation system. No questions were asked about
billboards. The participants were given $120.00 in cash for their participation.
22
DATA REDUCTION
Eye Tracking Measures
The Multiple - Analysis of Psychophysical and Performance Signals (MAPPSTM) software was
used to reduce the eye tracking data. (36) The software integrates the video output from the scene
cameras with the output from the eye tracking software (e.g., gaze vectors). The analysis
software provides an interface in which the gaze vectors determined by the eye tracker can be
related to areas or objects in the scene camera view of the world. Analysts can indicate regions of
interest (ROIs) in the scene camera views and the analysis software then assigns gaze vectors to
the ROIs.
Figure 9 shows a screen capture from the analysis software in which static ROIs have been
identified. These static ROIs slice up the scene camera views into six areas. The software also
allows for the construction of dynamic ROIs. These are ROIs that move in the video because of
own - vehicle movement (e.g., a sign changes position on the display as it is approached by the
driver) or because the object moves over time independent of own - vehicle movement (e.g.,
pedestrian walking along the road, vehicle entering or exiting the road).
Static ROIs need only be entered once for the scenario being analyzed whereas dynamic ROIs
need to be entered several times for a given DCZ depending on how the object moves along the
video scene; however, not every frame needs to be coded with a dynamic ROI since the software
interpolates across frames using the 60 -Hz data to compute eye movement statistics.
T f `W- s J
Jr
e'jk
Figure 9. Screen capture showing static ROIs on a scene video output.
The following ROIs were defined with the analysis software:
Static ROIs
These ROIs were entered once into the software for each participant. The static ROIs for the
windshield were divided into top and bottom to have more resolution during the coding process.
The subsequent analyses in the report combines the top and bottom portion of these ROIs since it
appeared that this additional level of resolution was not needed in order to address research
questions:
• Road ahead: bottom portion (approximately 2/3) of the area of the forward roadway
(center camera).
23
• Road ahead top: top portion (approximately 1/3) of the area of the forward roadway
(center camera).
• Right side of road bottom: bottom portion (approximately 2/3) of the area to the right of
the forward roadway (right camera).
• Right side of road top: top portion (approximately 1/3) of the area to the right of the
forward roadway (right camera).
• Left side of road bottom (LSR_B): bottom portion (approximately 2/3) of the area to the
left of the forward roadway (left camera).
• Left side of road bottom (LSR_T): top portion (approximately 1/3) of the area to the left
of the forward roadway (left camera).
• Inside vehicle: below the panoramic video scene (outside of the view of the cameras, but
eye tracking is still possible).
• Top: above the panoramic video scene (outside of the view of the cameras, but eye
tracking is still possible).
Dynamic ROA
These ROIs are created multiple times within a DCZ for stimuli that move relative to the driver:
• Driving- related safety risk: vehicle which posed a potential safety risk to the driver,
defined as a car that is /may turn into the driver's direction of travel at a non - signalized or
non - stop - controlled intersection (e.g., a car making a U -turn, a car waiting to turn right,
or a car waiting to turn left). These vehicles were actively turning or entering the roadway
or appeared to be in a position to enter the roadway.
• Target standard billboard: target standard billboard that defines the start and end of the
DCZ.
• Other standard billboard: standard billboard(s) located in the DCZ, other than the target
standard billboard or the target digital billboard.
• CEVMS: target digital billboard that defines the start and end of the DCZ.
The software determines the gaze intersection for each 60 Hz frame and assigns it to an ROI. In
subsequent analyses and discussion, gaze intersections are referred to as gazes. Since ROIs may
overlap, the software allows for the specification of priority for each ROI such that the ROI with
the highest priority gets the gaze vector intersection assigned to it. For example, an ROI for a
CEVMS may also be in the static ROI for the road ahead.
24
The 60 Hz temporal resolution of the eye tracking software does not provide sufficient
information to make detailed analysis of saccade characteristics, i such as latency or speed. The
analysis software uses three parameters in the determination of a fixation: a fixation radius,
fixation duration, and a time out. The determination begins with a single -gaze vector
intersection. Any subsequent intersection within a specified radius will be considered part of a
fixation if the minimum fixation duration criterion is met. The radius parameter used in this
study was 2 degrees and the minimum duration was 100 ms. The 2- degree selection was based
on the estimated accuracy of the eye tracking system, as recommended by Recarte and Nunes. (37)
The 100 ms minimum duration is consistent with many other published studies; however, some
investigators use minimums of as little as 60 ms. 37,3s Because of mini - saccades and noise in the
eye tracking system, it is possible to have brief excursions outside the 2 degree window for a
fixation. In this study, an excursion time outside the 2- degree radius of less than 90 ms was
ignored. Once the gaze intersection fell outside the 2- degree radius of a fixation for more than
90 ms, the process of identifying a fixation began anew.
Other Measures
Driving Behavior Measures
During data collection, the front -seat researcher observed the driver's behavior and the driving
environment. The researcher used the following subjective categories in observing the
participant's driving behavior:
• Driver Error: signified any error on behalf of the driver in which the researcher felt
slightly uncomfortable, but not to a significant degree (e.g., driving on an exit ramp too
quickly, turning too quickly).
Near Miss: signified any event in which the researcher felt uncomfortable due to driver
response to external sources (e.g., slamming on brakes, swerving). A near miss is the
extreme case of a driver error.
Incident: signified any event in the roadway which may have had a potential impact on
the attention of the driver and /or the flow of traffic (e.g., crash, emergency vehicle,
animal, construction, train).
These observations were entered into a notebook computer linked to the research vehicle data
collection system.
Level of Service Estimates
For each participant and each DCZ the analyst estimated the level of service of the road as they
reviewed the scene camera video. One location per DCZ was selected (approximately halfway
through the DCZ) where the number of vehicles in front of the research vehicle was counted.
The procedure entailed (1) counting the number of travel lanes visible in the video, (2) using the
i During visual scanning the point of gaze alternates between brief pauses (ocular fixations) and rapid shifts
(saccades).
25
skip lines on the road to estimate the approximate distance in front of the vehicle that constituted
the analysis zone, and (3) counting the number of vehicles present within the analysis zone.
Vehicle density was calculated with the formula:
Vehicle Density = [(Number of Vehicles in Analysis Zone) /(Distance of Analysis
Zone in ft/5280)]/Number of Lanes.
Vehicle density is the number of vehicles per mile per lane.
Vehicle Speed
The speed of the research vehicle was recorded with GPS and a distance measurement
instrument. Vehicle speed was used principally to ensure that the eye tracking data was recorded
while the vehicle was in motion.
RESULTS
Results are presented with respect to the photometric measures of signs, the visual complexity of
the DCZs, and the eye tracking measures. Photometric measurements were taken and analyzed to
characterize the billboards in the study based on their luminance and contrasts, which are related
to how bright the signs are perceived to be by drivers.
Photometric Measurements
Luminance
The mean daytime luminance of both the standard billboards and CEVMS was greater than at
night. Nighttime luminance measurements reflect the fact that CEVMS use illuminating LED
components while standard billboards are often illuminated from below by metal halide lamps.
At night, CEVMS have a greater average luminance than standard billboards. Table 3 presents
summary statistics for luminance as a function of time of day for the CEVMS and standard
billboards.
Contrast
The daytime and nighttime Weber contrast ratios for both types of billboards are shown in
table 3. Both CEVMS and standard billboards had contrast ratios that were close to zero (the
surroundings were about equal in brightness to the signs) during the daytime. On the other hand,
at night the CEVMS and standard billboards had positive contrast ratios (the signs were brighter
than the surrounding), with the CEVMS having higher contrast than the standard billboards.
26
Table 3. Summary of luminance (cd /m2) and contrast (Weber ratio) measurements.
Luminance (cd1m2)
Contrast
Day
Mean St. Dev.
Mean St .Dev.
CEVMS
2126 798.81
-0.10 0.54
Standard Billboard
2993 2787.22
-0.27 0.84
Night
CEVMS
56.00 23.16
73.72 56.92
Standard Billboard
17.80 17.11
36.01 30.93
Visual Complexity
The DCZs were characterized by their overall visual complexity or clutter. For each DCZ, five
pictures were taken from the driver's viewpoint at various locations within the DCZ. In Reading,
the pictures were taken from 2:00 p.m. to 4:00 p.m. In Richmond, one route was photographed
from 11:00 a.m. to noon and the other from 2:30 p.m. to 3:30 p.m. The pictures were taken at the
start of the DCZ, quarter of the way through, half of the way through, three quarters of the way
through, and at the end of the DCZ. The photographs were analyzed with MATLAB® routines
that computed a measure of feature congestion for each image. Figure 10 shows the mean feature
congestion measures for each of the DCZ environments. The arterial control condition was
shown to have the highest level of clutter as measured by feature congestion. An analysis of
variance was performed on the feature congestion measure to determine if the conditions differed
significantly from each other. The four conditions with off - premise advertising did not differ
significantly with respect to feature congestion; F(3,36) = 1.25, p > 0.05. Based on the feature
congestion measure, the results indicate that the four conditions with off - premise advertising
were equated with respect to the overall visual complexity of the driving scenes.
4.50
4.00 ■ Arterial
c 3.50
Highway
U 3.00 _
2.50 I I
2.00
1.50
1.00
0.50
0.00
Control CEVMS Standard
Advertising Conditions
Figure 10. Mean feature congestion as a function of advertising condition and road type
(standard errors for the mean are included in the graph).
27
Effects of Billboards on Gazes to the Road Ahead
For each 60 Hz frame, a determination was made as to the direction of the gaze vector. Previous
research has shown that gazes do not need to be separated into saccades and fixations before
calculating such measures as percent of time or the probability of looking to the road ahead. (39)
This analysis examines the degree to which drivers gaze toward the road ahead across the
different advertising conditions as a function of road type and time of day. Gazing toward the
road ahead is critical for driving, and so the analysis examines the degree to which gazes toward
this area are affected by the independent variables (advertising type, type of road, and time of
day) and their interactions.
Generalized estimating equations (GEE) were used to analyze the probability of a participant
gazing at driving- related information. (40,41) The data for these analyses were not normally
distributed and included repeated measures. The GEE model is appropriate for these types of
data and analyses. Note that for all results included in this report, Wald statistics were the chosen
alternative to likelihood ratio statistics because GEE uses quasi - likelihood instead of maximum
likelihood. (42) For this analysis, road ahead included the following ROIs (as previously described
and displayed in figure 9): road ahead, road ahead top, and driving- related risks. A logistic
regression model for repeated measures was generated by using a binomial response distribution
and Logit (i.e., log odds) link function. Only two possible outcomes are allowed when selecting a
binomial response distribution. Thus, a variable (RoadAhead) was created to classify a
participant's gaze behavior. If the participant gazed toward the road ahead, road ahead top, or
driving- related risks, then the value of RoadAhead was set to one. If the participant gazed at any
other object in the panoramic scene, then the value of RoadAhead was set to zero. Logistic
regression typically models the probability of a success. In the current analysis, a success would
be a gaze to road ahead information (RoadAhead = 1) and a failure would be a gaze toward non -
road ahead information (RoadAhead = 0). The resultant value was the probability of a participant
gazing at road -ahead information.
Time of day (day or night), road type (freeway or arterial), advertising condition (CEVMS,
standard billboard, or control), and all corresponding second -order interactions were explanatory
variables in the logistic regression model. The interaction of advertising condition by road type
was statistically significant, x2 (2) = 6.3, p = 0.043. Table 4 shows the corresponding
probabilities for gazing at the road ahead as a function of advertising condition and road type.
Table 4. The probability of gazing at the road ahead as a function of advertising condition
and road type.
Advertising Condition Arterial Freeway
Control 0.92 0.86
CEVMS 0.82 0.73
Standard 0.80 0.77
Follow -up analyses for the interaction used Tukey- Kramer adjustments with an alpha level of
0.05. The arterial control condition had the greatest probability of looking at the road ahead
(M = 0.92). This probability differed significantly from the remaining five probabilities. On
arterials, the probability of gazing at the road ahead did not differ between the CEVMS
(M = 0.82) and the standard billboard (M = 0.80) DCZs. In contrast, there was a significant
difference in this probability on freeways, where standard billboard DCZs yielded a higher
probability (M = 0.77) than CEVMS DCZs (M = 0.73). The probability of gazing at the road
ahead was also significantly higher in the freeway control DCZ (M = 0.86) than in either of the
corresponding freeway off - premise advertising DCZs. The probability of gazing at road -ahead
information in arterial CEVMS DCZs was not statistically different from the same probability in
the freeway control DCZ.
Additional descriptive statistics were computed to determine the probability of gazing at the
various ROIs that were defined in the panoramic scene. Some of the ROIs depicted in figure 9
were combined in the following fashion for ease of analysis:
• Road ahead, road ahead top, and driving - related risks combined to form road ahead.
• Left side of road bottom and left side of road top combined to form left side of vehicle.
• Right side of road bottom and right side of road top combined to form right side of
vehicle.
• Inside vehicle and top combined to form participant vehicle.
Table 5 presents the probability of gazing at the different ROIs.
Table 5. Probability of gazing at ROIs for the three advertising conditions on arterials and
freeways.
Road Tj
Arterial
Standard
ROI CEVMS Billboard Control
CEVMS
Left Side of Vehicle
Road ahead
Right Side of Vehicle
Standard Billboard
Participant Vehicle
0.07
N/A
N/A
0.06
0.06
0.02
0.82
0.80
0.92
0.03
0.06
0.04
N/A
0.03
N/A
0.03
0.05
0.02
Freeway CEVMS
0.05
N/A
N/A
Left Side of Vehicle
0.08
0.07
0.04
Road ahead
0.73
0.77
0.86
Right Side of Vehicle
0.09
0.02
0.05
Standard Billboard
0.02*
0.09
N/A
Participant Vehicle
0.04
0.05
0.05
* The CEVMS DCZs on freeways each contained one visible standard billboard.
The probability of gazing away from the forward roadway ranged from 0.08 to 0.27. In
particular, the probability of gazing toward a CEVMS was greater on arterials (M = 0.07) than on
freeways (M = 0.05). In contrast, the probability of gazing toward a target standard billboard was
greater on freeways (M = 0.09) than on arterials (M = 0.03).
29
Fixations to CEVMS and Standard Billboards
About 2.4 percent of the fixations were to CEVMS. The mean fixation duration to a CEVMS
was 388 ms and the maximum duration was 1,251 ms. Figure 11 shows the distribution of
fixation durations to CEVMS during the day and night. In the daytime, the mean fixation
duration to a CEVMS was 389 ms and at night it was 387 ms. Figure 12 shows the distribution of
fixation durations to standard billboards. Approximately 2.4 percent of fixations were to standard
billboards. The mean fixation duration to standard billboards was 341 ms during the daytime and
370 ms at night. The maximum fixation duration to standard billboards was 1,284 ms (which
occurred at night). For comparison purposes, figure 13 shows the distribution of fixation
durations to the road ahead (i.e., top and bottom road ahead ROIs) during the day and night. In
the daytime, the mean fixation duration to the road ahead was 365 ms and at night it was 390 ms.
60
40
U �
C
m
ii
m 0
0
F
a
v 60
N
a
110
20
Percentage Distribution of Fixation Duration
CEVMS Fxatio-is
300 7CO 1.100 1.590 1.900
500 OOC 1.300 '•700 > 2.DGD
Da-at or. (ms)
Figure 11. Distribution of fixation duration for CEVMS in the daytime and nighttime.
30
60
40
U �
C
m
ii
0
0
F
a
v 60
N
a
110
20
n
Percentage Distribution of Fixation Duration
Standard Billboard - ixatiZ)Is
300 7CO 1.100 1.590 1.900
500 OOC 1.300 ',700 2.:)GD
Da-at or. (ms)
Figure 12. Distribution of fixation duration for standard billboards in the daytime and
nighttime.
Percentage Distribution of Fixation Duration
Road Ahead [fop and Bottom] Fixalions
60
40
U 20
C
m
ii
0
0
F
a
v 60
N
a
110
20
0
300 7Cp 1.100 1.590 1.900
500 OOC 1.300 700 2.DGD
Da-at or. (ms)
Figure 13. Distribution of fixation duration for road ahead (i.e., top and bottom road ahead
ROIs) in the daytime and nighttime.
31
Dwell times on CEVMS and standard billboards were also examined. Dwell time is the duration
of back -to -back fixations to the same ROL(""') The dwell times represent the cumulative time
for the back -to -back fixations. Whereas there may be no long, single fixation to a billboard, there
might still be multiple fixations that yield long dwell times. There were a total of 25 separate
instances of multiple fixations to CEVMS with a mean of 2.4 fixations (minimum of 2 and
maximum of 5). The 25 dwell times came from 15 different participants distributed across four
different CEVMS. The mean duration of these dwell times was 994 ms (minimum of 418 ms and
maximum of 1,467 ms).
For standard billboards, there were a total of 17 separate dwell times with a mean of 3.47
sequential fixations (minimum of 2 fixations and maximum of 8 fixations). The 17 dwell times
came from 11 different participants distributed across 4 different standard billboards. The mean
duration of these multiple fixations was 1,172 ms (minimum of 418 ms and maximum of
3,319 ms). There were three dwell -time durations that were greater than 2,000 ms. These are
described in more detail below.
In some cases several dwell times came from the same participant. In order to compute a statistic
on the difference between dwell times for CEVMS and standard billboards, average dwell times
were computed per participant for the CEVMS and standard billboard conditions. These average
values were used in a Mest assuming unequal variances. The difference in average dwell time
between CEVMS (M = 981 ms) and standard billboards (M= 1,386 ms) was not statistically
significant, t(12) _ -1.40,p >.05.
Figure 14 through figure 23 show heat maps for the dwell -time durations to the standard
billboards that were greater than 2,000 ms. These heat maps are snapshots from the DCZ and
attempt to convey in two dimensions the pattern of gazes that took place in a three dimensional
world. The heat maps are set to look back approximately one to two seconds and integrate over
time where the participant was gazing in the scene camera video. The green color in the heat map
indicates the concentration of gaze over the past one to two seconds. The blue line indicates the
gaze trail over the past one to two seconds.
Figure 14 through figure 16 are for a DCZ on an arterial at night. The standard billboard was on
the right side of the road (indicated by a pink rectangle). There were eight fixations to this
billboard, and the single fixations were between 200 to 384 ms in duration. The dwell time for
this billboard was 2,019 ms. At the start of the DCZ (see figure 14), the driver was directing
his /her gaze to the forward roadway. Approaching the standard billboard, the driver began to
fixate on the billboard. However, the billboard was still relatively close to the road ahead ROI.
32
Figure 14. Heat map for the start of a DCZ for a standard billboard at night on an arterial.
Figure 15. Heat map for the middle of a DCZ for a standard billboard at night on an
arterial.
Figure 16. Heat map near the end of a DCZ for a standard billboard at night on an arterial.
Figure 17 through figure 19 are for a DCZ on a freeway at night. The standard billboard was on
the right side of the road (indicated by a green rectangle). There were six consecutive fixations to
this billboard, and the single fixations were between 200 and 801 ms in duration. The dwell time
for this billboard was 2,753 ms. At the start of the DCZ (see figure 17), the driver was directing
his /her gaze to a freeway guide sign in the road ahead and the standard billboard was to the left
of the freeway guide sign. As the driver approached the standard billboard, his /her gaze was
directed toward the billboard. The billboard was relatively close to the top and bottom road
ahead ROIs. Near the end of the DCZ (see figure 19), the billboard was accurately portrayed as
being on the right side of the road.
33
Figure 17. Heat map for start of a DCZ for a standard billboard at night on a freeway.
Figure 18. Heat map for middle of a DCZ for a standard billboard at night on a freeway.
Figure 19. Heat map near the end of a DCZ for a standard billboard at night on a freeway.
Figure 20 through figure 23 are for a DCZ on a freeway during the day. The standard billboard
was on the right side of the road (indicated by a pink rectangle). This is the same DCZ that was
discussed in figure 17 through figure 19. There were six consecutive fixations to this billboard,
and the single fixations were between 217 and 767 ms in duration. The dwell time for this
billboard was 3,319 ms. At the start of the DCZ (see figure 20), the driver was principally
directing his /her gaze to the road ahead. Figure 21 and figure 22 show the location along the
DCZ where gaze was directed toward the standard billboard. The billboard was relatively close
to the top and bottom road -ahead ROIs. As the driver passed the standard billboard, his /her gaze
returned to the road ahead (see figure 23).
34
Figure 20. Heat map for the start of a DCZ for a standard billboard in the daytime on a
freeway.
i.
I;
Ip
Figure 21. Heat map near the middle of a DCZ for a standard billboard in the daytime on a
freeway.
f
I.
Figure 22. Heat map near the end of DCZ for standard billboard in the daytime on a
freeway.
y
Figure 23. Heat map at the end of DCZ for standard billboard in the daytime on a freeway.
35
Comparison of Gazes to CEVMS and Standard Billboards
The GEE were used to analyze whether a participant gazed more toward CEVMS than toward
standard billboards, given that the participant was gazing at off - premise advertising. With this
analysis method, a logistic regression model for repeated measures was generated by using a
binomial response distribution and Logit link function. First, the data was partitioned to include
only those instances when a participant was gazing toward off - premise advertising (either to a
CEVMS or to a standard billboard); all other gaze behavior was excluded from the input data set.
Only two possible outcomes are allowed when selecting a binomial response distribution. Thus,
a variable (SBB_CEVMS) was created to classify a participant's gaze behavior. If the participant
gazed toward a CEVMS, the value of SBB_CEVMS was set to one. If the participant gazed
toward a standard billboard, then the value of SBB CEVMS was set to zero.
Logistic regression typically models the probability of a success. In the current analysis, a
success would be a gaze to a CEVMS (SBB_CEVMS = 1) and a failure would be a gaze to a
standard billboard (SBB_CEVMS = 0).' A success probability greater than 0.5 indicates there
were more successes than failures in the sample. Therefore, if the sample probability of the
response variable (i.e., SBB_CEVMS) was greater than 0.5, this would show that participants
gazed more toward CEVMS than toward standard billboards when the participants gazed at off -
premise advertising. In contrast, if the sample probability of the response variable was less than
0.5, then participants showed a preference to gaze more toward standard billboards than toward
CEVMS when directing gazes to off - premise advertising.
Time of day (i.e., day or night), road type (i.e., freeway or arterial), and the corresponding
interaction were explanatory variables in the logistic regression model. Road type was the only
predictor to have a significant effect, x' (1) = 13.17,p < 0.001. On arterials, participants gazed
more toward CEVMS than toward standard billboards (M = 0.63). In contrast, participants gazed
more toward standard billboards than toward CEVMS when driving on freeways (M = 0.33).
Observation of Driver Behavior
No near misses or driver errors were observed in Reading.
Level of Service
The mean vehicle densities were converted to level of service as shown in table 6.(45) As
expected, less congestion occurred at night than in the day. In general, there was traffic during
the data collection runs. Review of the scene camera data verified that all eye tracking data
within the DCZs were recorded while the vehicle was in motion.
2 Success and failure are not used to reflect the merits of either type of sign, but only for statistical purposes.
36
Table 6. Level of service as a function of advertising type, road type, and time of day.
Arterial Freeway
Day Night Day Night
Control B A C B
CEVMS C A B A
Standard A A B A
DISCUSSION OF READING RESULTS
Overall the probability of gazing at the road ahead was high and similar in magnitude to what
has been found in other field studies addressing billboards.("",") For the DCZs on freeways,
CEVMS showed a lower proportion of gazes to the road ahead than the standard billboard
condition, and both off - premise advertising conditions had lower probability of gazes to the road
ahead than the control. On the other hand, on the arterials, the CEVMS and standard billboard
conditions did not differ from each other but were significantly different from their respective
control condition. Though the CEVMS condition on the freeway had the lowest proportion of
gazes to the road ahead, in this condition there was a lower proportion of gazes to CEVMS as
compared to the arterials (see table 5 for the trade -off of gazes to the different ROIs). A greater
proportion of gazes to other ROIs (left side of the road, right side of the road, and participant
vehicle) contributed to the decrease in proportion of gazes to the road ahead. Also, for the
CEVMS on freeways, there were a few gazes to a standard billboard located in the same DCZ
and there were more gazes distributed to the left and right side of the road than in standard
billboard and control conditions. The gazes to ROIs other than CEVMS contributed to the lower
probability of gazes to the road ahead in this condition.
The control condition on the arterial had buildings along the sides of the road and generally
presented a visually cluttered area. As was presented earlier, the feature congestion measure
computed on a series of photographs from each DCZ showed a significantly higher feature
congestion score for the control condition on arterials as compared to all of the other DCZs.
Nevertheless, the highest probability for gazing at the road ahead was seen in the control
condition on the arterial.
The area with the highest feature congestion, especially on the sides of the road, had the highest
probability for drivers looking at the road ahead. Bottom -up or stimulus driven measures of
salience or visual clutter have been useful in predicting visual search and the effects of visual
salience in laboratory tasks. (34,46) These measures of salience basically consider the stimulus
characteristics (e.g., size, color, brightness) independent of the requirements of the task or plans
that an individual may have. Models of visual salience may predict that buildings and other
prominent features on the side of the road may be visually salient objects and thus would attract
a driver's attention. (47) Figure 24 shows an example of a roadway photograph that was analyzed
with the Salience Toolbox based on the Itti et al. implementation of a saliency based model of
bottom -up attention. (41,49) The numbered circles in figure 24 are the first through fifth salient
areas selected by the software. Based on this software, the most salient areas in the photographs
are the buildings on the sides of the road where the road ahead (and a car) is the fifth selected
salient area.
37
Figure 24. Example of identified salient areas in a road scene based on bottom -up analysis.
It appears that in the present study participants principally kept their eyes on the road even in the
presence of visual clutter on the sides of the road, which supports the hypothesis that drivers tend
to look toward information relevant to the task at hand. (10,26,22) In the case of the driving task,
visual clutter may be more of an issue with respect to crowding that may affect the driver's
ability to detect visual information in the periphery. (51) Crowding is generally defined as the
negative effect of nearby objects or features on visual discrimination of a target. (52) Crowding
impairs the ability to recognize objects in clutter and principally affects perception in peripheral
vision. However, crowing effects were not analyzed in the present study.
Stimulus salience, clutter, and the nature of the task at hand interact in visual perception. For
tasks such as driving, the task demands tend to outweigh stimulus salience when it comes to gaze
control. Clutter may be more of an issue with the detection and recognition of objects in
peripheral vision (e.g., detecting a sign on the side of the road) that are surrounded by other
stimuli that result in a crowding effect.
The mean fixation durations to CEVMS, standard billboards, and the road ahead were found to
be very similar. Also, there were no long fixations (greater than 2,000 ms) to CEVMS or
standard billboards. The examination of multiple sequential fixations to CEVMS yielded average
dwell times that were less than 1,000 ms. However, when examining the tails of the distribution,
there were three dwell times to standard billboards that were in excess of 2,000 ms (the three
dwell times came from three different participants to two different billboards). These three
standard billboards were dwelled upon when they were near the road ahead area but drivers quit
gazing at the signs as they neared them and the signs were no longer near the forward field of
view. Though there were three dwell times for standard billboards greater than 2,000 ms, the
difference in average dwell times for CEVMS and standard billboards was not significant.
Using a gaze duration of 2,000 ms away from the road ahead as a criterion indicative of
increased risk has been developed principally as it relates to looking inside the vehicle to in-
vehicle information systems and other devices (e.g., for texting) where the driver is indeed
looking completely away from the road ahead. (14,53,54) The fixations to the standard billboards in
the present case showed a long dwell time for a billboard. However, unlike gazing or fixating
inside the vehicle, the driver's gaze was within the forward roadway where peripheral vision
could be used to monitor for hazards and for vehicle control. Peripheral vision has been shown to
be important for lane keeping, visual search orienting, and monitoring of surrounding
obi ects. (55,56)
i
The results showed that drivers were more likely to gaze at CEVMS on arterials and at standard
billboards on freeways. Though every attempt was made to select CEVMS and standard
billboard DCZs that were equated on important parameters (e.g., which side of the road the sign
was located on, type of road, level of visual clutter), the CEVMS DCZs on freeways had a
greater setback from the road (133 ft for both CEVMS) than the standard billboards (10 and
35 ft). Signs with greater setback from the road would in a sense move out of the forward view
(road ahead) more quickly than signs that are closer to the road. The CEVMS and standard
billboards on the arterials were more closely matched with respect to setback from the road (12
and 43 ft for CEVMS and 20 and 40 ft for standard billboards).
The differences in setback from the road for CEVMS and standard billboards may also account
for differences in dwell times to these two types of billboards. However, on arterials where the
CEVMS and standard billboards were more closely matched there was only one long dwell time
(greater than 2,000 ms) and it was to a standard billboard at night.
39
RICHMOND
The objectives of the second study were the same as those in the first study, and the design of the
Richmond data collection effort was very similar to that employed in Reading. This study was
conducted to replicate as closely as possible the design of Reading in a different driving
environment. The independent variables included the type of DCZ (CEVMS, standard billboard,
or no off - premise advertising), time of day (day or night) and road type (freeway or arterial). As
with Reading, the time of day was a between - subjects variable and the other variables were
within subjects.
METHOD
Selection of DCZ Limits
Selection of the DCZ limits procedure was the same as that employed in Reading.
Advertising Type
Three DCZ types (similar to those used in Reading) were used in Richmond:
• CEVMS. DCZs contained one target CEVMS.
• Standard billboard. DCZs contained one target standard billboard.
• Control conditions. DCZs did not contain any off - premise advertising.
There were an equal number of CEVMS and standard billboard DCZs on freeways and arterials.
Also, there two DCZ that did not contain off - premise advertising with one located on a freeway
and the other on an arterial.
Table 7 is an inventory of the target employed in this second study.
Table 7. Inventory of target billboards in Richmond with relevant parameters.
Advertising
Copy
Side of
Setback
Other
Approach
Roadway
DCZ
Type
Dimensions
Road
fi.om Road
Standard
Length (ft)
Type
t
t
Billboards
5
CONTROL
N/A
N/A
N/A
N/A
710
Arterial
3
CONTROL
N/A
N/A
N/A
N/A
845
Freeway
9
CEVMS
14'0" x 28'0"
L
37
0
696
Arterial
13
CEVMS
14'0" x 28'0"
R
37
0
602
Arterial
2
CEVMS
12'5" x40'0"
R
91
0
297
Freeway
8
CEVMS
11'0 x 23'0"
L
71
0
321
Freeway
10
Standard
14'0" x 48'0"
L
79
1
857
Arterial
12
Standard
10'6" x 45'3"
R
79
2
651
Arterial
1
Standard
14'0" x 48'0"
L
87
0
997
Freeway
7
Standard
14'0" x 48'0"
R
88
0
816
Freeway
* N/A indicates that there were no off-premise advertising in these areas and these values are undefined
.e
Figure 25 through figure 30 below represent various pairings of DCZ type and road type. Target
off - premise billboards are indicated by red rectangles.
Figure 25. Example of a CEVMS DCZ on a freeway.
Figure 26. Example of CEVMS DCZ an arterial.
Figure 27. Example of a standard billboard DCZ on a freeway.
41
Figure 28. Example of a standard billboard DCZ on an arterial.
Figure 29. Example of a control DCZ on a freeway.
Figure 30. Example of a control DCZ on an arterial.
Photometric Measurement of Signs
The methods and procedures for the photometric measures were the same as for Reading.
Visual Complexity
The methods and procedures for visual complexity measurement were the same as for Reading.
42
Participants
A total of 41 participants were recruited for the study. Of these, 6 participants did not complete
data collection because of an inability to properly calibrate with the eye tracking system, and 11
were excluded because of equipment failures. A total of 24 participants (13 male, M = 28 years;
11 female, M = 25 years) successfully completed the drive. Fourteen people participated during
the day and 10 participated at night.
Procedures
Research participants were recruited locally by means of visits to public libraries, student unions,
community centers, etc. A large number of the participants were recruited from a nearby
university, resulting in a lower mean participant age than in Reading.
Participant Testing
Two people participated each day. One person participated during the day beginning at
approximately 12:45 p.m. The second participated at night beginning at around 7:00 p.m. Data
collection ran from November 20, 2009, through April 23, 2010. There were several long gaps in
the data collection schedule due to holidays and inclement weather.
Pre -Data Collection Activities
This was the same as in Reading.
Practice Drive
Except for location, this was the same as in Reading.
Data Collection
The procedure was much the same as in Reading. On average, each test route required
approximately 30 to 35 minutes to complete. As in Reading, the routes included a variety of
freeway and arterial driving segments. One route was 15 miles long and contained two target
CEVMS, two target standard billboards, and two DCZs with no off - premise advertising. The
second route was 20 miles long and had two target CEVMS and two target standard billboards.
The data collection drives in this second study were longer than those in Reading. The eye
tracking system had problems dealing with the large files that resulted. To mitigate this technical
difficulty, participants were asked to pull over in a safe location during the middle of each data
collection drive so that new data files could be initiated.
Upon completion of the data collection, the participant was instructed to return to the designated
meeting location for debriefing.
Debriefing
This was the same as in Reading.
43
DATA REDUCTION
Eye Tracking Measures
The approach and procedures were the same as used in Reading.
Other Measures
The approach and procedures were the same as used in Reading.
RESULTS
Photometric Measurement of Signs
The photometric measurements were performed using the same equipment and procedures that
were employed in Reading with a few minor changes. Photometric measurements were taken
during the day and at night. Measurements of the standard billboards were taken at an average
distance of 284 ft, with maximum and minimum distances of 570 ft and 43 ft, respectively. The
average distance of measurements for the CEVMS was 479 ft, with maximum and minimum
distances of 972 ft and 220 ft, respectively. Again, the distances employed were significantly
affected by the requirement to find a safe location on the road from which to take the
measurements.
Luminance
The mean luminance of CEVMS and standard billboards, during daytime and nighttime are
shown below in table 8. The results here are similar to those for Reading.
Contrast
The daytime and nighttime Weber contrast ratios for both types of billboards are shown in
table 8. During the day, the contrast ratios of both CEVMS and standard billboards were close to
zero (the surroundings were about equal in brightness to the signs). At night, the CEVMS and
standard billboards had positive contrast ratios. Similar to Reading, the CEVMS showed a higher
contrast ratio than the standard billboards at night.
Table 8. Summary of luminance (cd /m2) and contrast (Weber ratio) measurements.
..
Luminance (cdlW)
Contrast
Day
Mean
St. Dev.
Mean
St. Dev.
CEVMS
Standard Billboard
2134
3063
798.70
2730.92
-0.20
0.03
0.53
0.32
Night
CEVMS
Standard Billboard
56.44
8.00
16.61
5.10
69.70
6.56
59.18
3.99
..
Visual Complexity
As with Reading, the feature congestion measure was used to estimate the level of visual
complexity /clutter in the DCZs. The analysis procedures were the same as for Reading.
Figure 31 shows the mean feature congestion measures for each of the advertising types
(standard errors are included in the figure). Unlike the results for Reading, the selected off -
premise advertising DCZs for Richmond differed in terms of mean feature congestion; F(3, 36) _
3.95, p = 0.016. Follow up t -tests with an alpha of 0.05 showed that the CEVMS DCZs on
arterials had significantly lower feature congestion than all of the other off - premise advertising
conditions. None of the remaining DCZs with off - premise advertising differed from each other.
The selection of DCZs for the conditions with off - premise advertising took into account the type
of road, the side of the road the target billboard was placed, and the perceived level of visual
clutter. Based on the feature congestion measure, these results indicated that the conditions with
off - premise advertising were not equated with respect to level of visual clutter.
4.50 ■ Arterial
4.00 Highway
c 3.50
U
3.00
O
L 2.50
2.00
ti
1.00
0.50
ME
Control CEVMS Standard
Advertising Condition
Figure 31. Mean feature congestion as a function of advertising condition and road type.
Effects of Billboards on Gazes to the Road Ahead
As was done for the data from Reading, GEE were used to analyze the probability of a
participant gazing at the road ahead. A logistic regression model for repeated measures was
generated by using a binomial response distribution and Logit link function. The resultant value
was the probability of a participant gazing at the road ahead (as previously defined).
Time of day (day or night), road type (freeway or arterial), advertising type ( CEVMS, standard
billboard, or control), and all corresponding second -order interactions were explanatory variables
in the logistic regression model. The interaction of advertising type by road type was statistically
significant, x2 (2) = 14.19, p < 0.001. Table 9 shows the corresponding probability of gazing at
the road ahead as a function of advertising condition and road type.
'•
Table 9. The probability of gazing at the road ahead as a function of advertising condition
and road type.
Advertising Condition
Arterial
Freeway
Control
0.78
0.92
CEVMS
0.76
0.82
Standard
0.81
0.85
Follow -up analyses for the interaction used Tukey- Kramer adjustments with an alpha level of
0.05. The freeway control had the greatest probability of gazing at the road ahead (M = 0.92).
This probability differed significantly from the remaining five probabilities. On arterials, there
were no significant differences among the probabilities of gazing at the road ahead among the
three advertising conditions. On freeways, there was no significant difference between the
probability associated with CEVMS DCZs and the probability associated with standard billboard
DCZs.
Additional descriptive statistics were computed for the three advertising types to determine the
probability of gazing at the ROIs that were defined in the panoramic scene. As was done with the
data from Reading, some of the ROIs were combined for ease of analysis. Table 10 presents the
probability of gazing at the different ROIs.
Table 10. Probability of gazing at ROIs for the three advertising conditions on arterials
and freeways.
Road Type ROI
CEVMS
Standard
Billboard
Control
Arterial CEVMS
0.06
N/A
N/A
Left Side of Vehicle
0.03
0.05
0.04
Road ahead
0.76
0.81
0.78
Right Side of Vehicle
0.07
0.06
0.09
Standard Billboard
N/A
0.02
N/A
Participant Vehicle
0.07
0.06
0.09
Freeway CEVMS
0.05
N/A
N/A
Left Side of Vehicle
0.03
0.01
0.01
Road ahead
0.82
0.85
0.92
Right Side of Vehicle
0.04
0.04
0.03
Standard Billboard
N/A
0.04
N/A
Participant Vehicle
0.06
0.06
0.05
The probability of gazing away from the forward roadway ranged from 0.08 to 0.24. In
particular, the probability of gazing toward a CEVMS was slightly greater on arterials
(M = 0.06) than on freeways (M = 0.05). In contrast, the probability of gazing toward a standard
billboard was greater on freeways (M = 0.04) than on arterials (M = 0.02). In both situations, the
probability of gazing at the road ahead was greatest on freeways.
EEO
Fixations to CEVMS and Standard Billboards
About 2.5 percent of the fixations were to CEVMS. The mean fixation duration to a CEVMS
was 371 ms and the maximum fixation duration was 1,335 ms. Figure 32 shows the distribution
of fixation durations to CEVMS during the day and at night. In the daytime, the mean fixation
duration to a CEVMS was 440 ms and at night it was 333 ms. Approximately 1.5 percent of the
fixations were to standard billboards. The mean fixation duration to standard billboards was
318 ms and the maximum fixation duration was 801 ms. Figure 33 shows the distribution of
fixation durations for standard billboards. The mean fixation duration to a standard billboard was
313 ms and 325 ms during the day and night, respectively. For comparison purposes, figure 34
shows the distribution of fixation durations to the road ahead during the day and night. In the
daytime, the mean fixation duration to the road ahead was 378 ms and at night it was 358 ms.
60
40
U �
C
m
ii
m 0
0
F
a
v 60
N
a
110
20
Percentage Distribution of Fixation Duration
CEVMS Fxatio-is
300 7CO 1.100 1.590 1.900
500 OOC 1.300 '•700 > 2.DGD
Da-at or. (ms)
Figure 32. Fixation duration for CEVMS in the day and at night.
47
Percentage Distribution of Fixation Duration
Slandard Billboards Fixations
60
40
U �
C
m
ii
0
0
F
a
v 60
N
a
110
20
n
300 7Cp 1.100 1.590 1.900
500 OOC 1.300 700 2.DGD
Da-at or. (ms)
Figure 33. Fixation duration for standard billboards in the day and at night.
60
40
U 20
C
m
ii
0
0
F
a
v 60
N
a
110
20
n
Percentage Distribution of Fixation Duration
Road Ahead [Top and Bottom] Fixal ions
300 7C0 1.100 1.590 1.900
500 OOC 1.300 ',700 2.DGD
Da-at or. (ms)
Figure 34. Fixation duration for the road ahead in the day and at night.
M.
As was done with the data for Reading, the record of fixations was examined to determine dwell
times to CEVMS and standard billboards. There were a total of 21 separate dwell times to
CEVMS with a mean of 2.86 sequential fixations (minimum of 2 fixations and maximum of 6
fixations). The 21 dwell times came from 12 different participants and four different CEVMS.
The mean dwell time duration to the CEVMS was 1,039 ms (minimum of 500 ms and maximum
of 2,720 ms). There was one dwell time greater than 2,000 ms to CEVMS. To the standard
billboards there were 13 separate dwell times with a mean of 2.31 sequential fixations (minimum
of 2 fixations and maximum of 3 fixations). The 13 dwell times came from 11 different
participants and four different standard billboards. The mean dwell time duration to the standard
billboards was 687 ms (minimum of 450 ms and maximum of 1,152 ms). There were no dwell
times greater than 2,000 ms to standard billboards.
In some cases several dwell times came from the same participant. To compute a statistic on the
difference between dwell times for CEVMS and standard billboards, average dwell times were
computed per participant for the CEVMS and standard billboard conditions. These average
values were used in a t -test assuming unequal variances. The difference in average dwell time
between CEVMS (M = 1,096 ms) and standard billboards (M= 674 ms) was statistically
significant, t(14) = 2.23, p = .043.
Figure 35 through figure 37 show heat maps for the dwell -time durations to the CEVMS that
were greater than 2,000 ms. The DCZ was on a freeway during the daytime. The CEVMS is
located on the left side of the road (indicated by an orange rectangle). There were three fixations
to this billboard, and the single fixations were between 651 ms and 1,335 ms. The dwell time for
this billboard was 2,270 ms. Figure 35 shows the first fixation toward the CEVMS. There are no
vehicles near the participant in his /her respective travel lane or adjacent lanes. In this situation,
the billboard is relatively close to the road ahead ROI. Figure 36 shows a heat map later in the
DCZ where the driver continues to look at the CEVMS. The heat map does not overlay the
CEVMS in the picture since the heat map has integrated over time where the driver was gazing.
The CEVMS has moved out of the area because of the vehicle moving down the road. However,
visual inspection of the video and eye tracking statistics showed that the driver was fixating on
the CEVMS. Figure 37 shows the end of the sequential fixations to the CEVMS. The driver
returns to gaze directly in front of the vehicle. Once the CEVMS was out of the forward field of
view, the driver quit looking at the billboard.
Figure 35. Heat map for first fixation to CEVMS with long dwell time.
. •
Figure 36. Heat map for later fixations to CEVMS with long dwell time.
Figure 37. Heat map at end of fixations to CEVMS with long dwell time.
Comparison of Gazes to CEVMS and Standard Billboards
As was done for the data from Reading, GEE were used to analyze whether a participant gazed
more toward CEVMS than toward standard billboards, given that the participant was looking at
off - premise advertising. Recall that a sample probability greater than 0.5 indicated that
participants gazed more toward CEVMS than standard billboards when the participants gazed at
off - premise advertising. In contrast, if the sample probability was less than 0.5, participants
showed a preference to gaze more toward standard billboards than CEVMS when directing
visual attention to off - premise advertising.
Time of day (i.e., day or night), road type (i.e., freeway or arterial), and the corresponding
interaction were explanatory variables in the logistic regression model. Time of day had a
significant effect on participant gazes toward off - premise advertising, X'(1) = 4.46,p = 0.035.
Participants showed a preference to gaze more toward CEVMS than toward standard billboards
during both times of day. During the day the preference was only slight (M = 0.52), but at night
the preference was more pronounced (M = 0.71). Road type was also a significant predictor of
where participants directed their gazes at off - premise advertising, x' (1) = 3.96, p = 0.047.
Participants gazed more toward CEVMS than toward standard billboards while driving on both
types of roadways. However, driving on freeways yielded a slight preference for CEVMS over
standard billboards (M = 0.55), but driving on arterials resulted in a larger preference in favor of
CEVMS (M = 0.68).
50
Observation of Driver Behavior
No near misses or driver errors occurred.
Level of Service
Table 11 shows the level of service as a function of advertising type, type of road, and time of
day. As expected, there was less congestion during the nighttime runs than in the daytime. In
general, there was traffic during the data collection runs; however, the eye tracking data were
recorded while the vehicles were in motion.
Table 11. Estimated level of service as a function of advertising condition, road type, and
time of day.
Arterial Freeway
Day Night Day Night
Control B A C B
CEVMS B A B A
Standard C A C C
DISCUSSION OF RICHMOND RESULTS
Overall the probability of looking at the forward roadway was high across all conditions and
consistent with the findings from Reading and previous related research.(", 9, 12) In this second
study the CEVMS and standard billboard conditions did not differ from each other. For the
DCZs on arterials there were no significant differences among the control, CEVMS, and
standard billboard conditions. On the other hand, while the CEVMS and standard billboard
conditions on the freeways did not differ from each other, they were significantly different from
their respective control conditions. The control condition on the freeway principally had trees
along the sides of the road and the signs that were present were freeway signs located in the road
ahead ROI.
Measures such as feature congestion rated the three DCZs on freeways as not being statistically
different from each other. These types of measures have been useful in predicting visual search
and the effects of visual salience in laboratory tasks. (34) Models of visual salience may predict
that, at least during the daytime, trees on the side of the road may be visually salient objects that
would attract a driver's attention. (47) However, it appears that in the present study, participants
principally kept their eyes on the road ahead.
The mean fixations to CEVMS, standard billboards, and the road ahead were found to be similar
in magnitude with no long fixations. Examination of dwell times showed that there was one long
dwell time for a CEVMS greater than 2,000 ms and it occurred in the daytime on a sign located
on the left side of the road on a freeway DCZ. Furthermore, when averaging among participants
the mean dwell time for CEVMS was significantly longer than to standard billboards, but still
under 2,000 ms. For the dwell time greater than 2,000 ms, examination of the scene camera
video and eye tracking heat maps showed that the driver was initially looking toward the forward
roadway and made a first fixation to the sign. Three fixations were made to the sign and then the
51
driver started looking back to the road ahead as the sign moved out of the forward field of view.
On the video there were no vehicles near the subject driver's own lane or in adjacent lanes.
Only the central 2 degrees of vision, foveal vision, provide resolution sharp enough for reading
or recognizing fine detail .(57) However, useful information for reading can be extracted from
parafoveal vision, which encompasses the central 10 degrees of vision. (57) More recent research
on scene gist recognition has shown that peripheral vision (beyond parafoveal vision) is more
useful than central vision for recognizing the gist of a scene. (58) Scene gist recognition is a
critically important early stage of scene perception, and influences more complex cognitive
processes such as directing attention within a scene and facilitating object recognition, both of
which are important in obtaining information while driving.
The results of this study do show one duration of eyes off the forward roadway greater than
2,000 ms, the duration at which Klauer et al. observed near - crash/crash risk at more than twice
those of normal, baseline driving. (14,53) When looking at the tails of the fixation distributions, few
fixations were greater than 1,000 ms, with the longest fixation being equal to 1,335 ms. (53,54) The
one long dwell time on a CEVMS that was observed was a rare event in this study, and review of
the video and eye tracking data suggests that the driver was effectively managing acquisition of
visual information while driving and fixated on the advertising. However, additional work needs
to be done to derive criteria for gazing or fixating away from the forward road view where the
road scene is still visible in peripheral vision.
The results showed that drivers are more likely to look at CEVMS than standard billboards
during the nighttime across the conditions tested (at night the average probability of gazing at
CEVMS was M= 0.71). CEVMS do have greater luminance than standard billboards at night and
also have higher contrast. The CEVMS have the capability of being lit up so that they would
appear as very bright signs to drivers (for example, up to about10,000 cd /m2 for a white square
on the sign.). However, our measurements of these signs showed an average luminance of about
56 cd /m2. These signs would be conspicuous in a nighttime driving environment but significantly
less so than other light sources such as vehicle headlights. Drivers were also more likely to look
at CEVMS than standard billboards on both arterials and freeways, with a higher probability of
gazes on arterials.
In this second study, CEVMS and standard billboards were more nearly equated with respect to
setback from the road. Gazes to the road ahead were not significantly different between CEVMS
and standard billboard DCZs across conditions and the proportion of gazes to the road ahead
were consistent with previous research. One long dwell time for a CEVMS was observed in this
study; however, it occurred in the daytime where the luminance and contrast (affecting the
perceived brightness) of these signs are similar to those for standard billboards.
3 ,Scene gist recognition" refers to the element of human cognition that enables us to determine the meaning of a
scene and categorize it by type (e.g., a beach, an office) almost immediately upon seeing it.
52
GENERAL DISCUSSION
This study was conducted to investigate the effect of CEVMS on driver visual behavior in a
roadway driving environment. An instrumented vehicle with an eye tracking system was used.
Roads containing CEVMS, standard billboards, and control areas with no off - premise
advertising were selected. The CEVMS and standard billboards were measured with respect to
luminance, location, size, and other relevant variables to characterize these visual stimuli. Unlike
previous studies on digital billboards, the present study examined CEVMS as deployed in two
United States cities and did not contain dynamic video or other dynamic elements. The CEVMS
changed content approximately every 8 to 10 seconds, consistent within the limits provided by
FHWA guidance. (2) In addition, the eye tracking system used had nearly a 2- degree level of
resolution that provided significantly more accuracy in determining what objects the drivers were
gazing or fixating on as compared to some previous field studies examining CEVMS.
CONCLUSIONS
Do CEVMS attract drivers' attention away from the forward roadway and other driving
relevant stimuli?
Overall, the probability of looking at the road ahead was high across all conditions. In Reading,
the CEVMS condition had a lower proportion of gazes to the road ahead than the standard
billboard condition on the freeways. Both of the off - premise advertising conditions had a lower
proportion of gazes to the road ahead than the control condition on the freeway. The lower
proportion of gazes to the road ahead can be attributed to the overall distribution of gazes away
from the road ahead and not just to the CEVMS. On the other hand, for the arterials the CEVMS
and standard billboard conditions did not differ from each other, but both had a lower proportion
of gazes to the road ahead compared to the control. In Richmond there were no differences
among the three advertising conditions on the arterials. However, for the freeways the CEVMS
and standard billboard conditions did not differ from each other but had a lower proportion of
gazes to the road ahead than the control.
The control conditions differed across studies. In Reading, the control condition on arterials
showed 92 percent for gazing at the road ahead while on the freeway it was 86 percent. On the
other hand, in Richmond the control condition for arterials was 78 percent and for the freeway it
was 92 percent. The control conditions on the freeway differed across the two studies. In
Reading there were businesses off to the side of the road; whereas in Richmond the sides of the
road were mostly covered with trees. The control conditions on the arterials also differed across
cities in that both contained businesses and on- premise advertising; however, in Reading arterials
had four lanes and in Richmond arterials had six lanes. The reason for these differences across
cities was that these control conditions were selected to match the other conditions ( CEVMS and
standard billboards) that the drivers would experience in the two respective cities. Also, the
selection of DCZs was obviously constrained by what was available on the ground in these cities.
The results for the off - premise advertising conditions are consistent with Lee et al., who
observed that 76 percent of drivers' time was spent lookin at the road ahead in the CEVMS
scenario and 75 percent in the standard billboard scenario. 9) However, it should be kept in mind
53
that drivers did gaze away from the road ahead even when no off - premise advertising was
present and that the presence of clutter or salient visual stimuli did not necessarily control where
drivers gazed.
Do glances to CEVMS occur that would suggest a decrease in safety?
In DCZs containing CEVMS, about 2.5 percent of the fixations were to CEVMS (about 2.4
percent to standard billboards). The results for fixations are similar to those reported in other
field data collection efforts that included advertising signs. (12,11,9,13) Fixations greater than
2,000 ms were not observed for CEVMS or standards billboards.
However, an analysis of dwell times to CEVMS showed a mean dwell time of 994 ms
(maximum of 1,467 ms) for Reading and a mean of 1,039 ms (maximum of 2,270 ms) for
Richmond. Statistical comparisons of average dwell times between CEVMS and standard
billboards were not significant in Reading; however, in Richmond the average dwell times to
CEVMS were significantly longer than to standard billboards, though below 2,000 ms. There
was one dwell time greater than 2,000 ms to a CEVMS across the two cities. On the other hand,
for standard billboards there were three long dwell times in Reading; there were no long dwell
times to these billboards in Richmond. Review of the video data for these four long dwell times
showed that the signs were not far from the forward view when participants were fixating.
Therefore, the drivers still had access to information about what was in front of them through
peripheral vision.
As the analyses of gazes to the road ahead showed, drivers distributed their gazes away from the
road ahead even when there were no off - premise billboards present. Also, drivers gazed and
fixated on off - premise signs even though they were generally irrelevant to the driving task.
However, the results did not provide evidence indicating that CEVMS were associated with long
glances away from the road that may reflect an increase in risk. When long dwell times occurred
to CEVMS or standard billboards, the road ahead was still in the driver's field of view.
Do drivers look at CEVMS more than at standard billboards?
The drivers were generally more likely to gaze at CEVMS than at standard billboards. However,
there was some variability between the two locations and between type of roadway (arterial or
freeway). In Reading, the participants looked more often at CEVMS when on arterials, whereas
they looked more often at standard billboards when on freeways. In Richmond, the drivers
looked at CEVMS more than standard billboards no matter the type of road they were on, but as
in Reading the preference for gazing at CEVMS was greater on arterials (68 percent on arterials
and 55 percent on freeways). The slower speed on arterials and sign placement may present
drivers with more opportunities to gaze at the signs.
In Richmond, the results showed that drivers gazed more at CEVMS than standard billboards at
night; however, for Reading no effect for time of day was found. CEVMS do have higher
luminance and contrast than standard billboards at night. The results showed mean luminance of
about 56 cd /m2 in the two cities where testing was conducted. These signs would appear clearly
visible but not overly bright.
54
SUMMARY
The results of these studies are consistent with a wealth of research that has been conducted on
vision in natural environments. (26,22,21) In the driving environment, gaze allocation is principally
controlled by the requirements of the task. Consistent results were shown for the proportion of
gazes to the road ahead for off - premise advertising conditions across the two cities. Average
fixations were similar to CEVMS and standard billboards with no long single fixations evident
for either condition. Across the two cities, four long dwell times were observed: one to a
CEVMS on a freeway in the day, two to the same standard billboard on a freeway (once at night
and once in the daytime), and one to a standard billboard on an arterial at night. Examination of
the scene video and eye tracking data indicated that these long dwell times occurred when the
billboards were close to the forward field of view where peripheral vision could still be used to
gather visual information on the forward roadway.
The present data suggest that the drivers in this study directed the majority of their visual
attention to areas of the roadway that were relevant to the task at hand (i.e., the driving task).
Furthermore, it is possible, and likely, that in the time that the drivers looked away from the
forward roadway, they may have elected to glance at other objects in the surrounding
environment (in the absence of billboards) that were not relevant to the driving task. When
billboards were present, the drivers in this study sometimes looked at them, but not such that
overall attention to the forward roadway decreased.
LIMITATIONS OF THE RESEARCH
In this study the participants drove a research vehicle with two experimenters on board. The
participants were provided with audio turn -by -turn directions and consequently did not have a
taxing navigation task to perform. The participants were instructed to drive as they normally
would. However, the presence of researchers in the vehicle and the nature of the driving task do
limit the degree to which one may generalize the current results to other driving situations. This
is a general limitation of instrumented vehicle research.
The two cities employed in the study appeared to follow common practices with respect to the
content change frequency (every 8 to 10 seconds) and the brightness of the CEVMS. The current
results would not generalize to situations where these guidelines are not being followed.
Participant recruiting was done through libraries, community centers and at a university. This
recruiting procedure resulted in a participant demographic distribution that may not be
representative of the general driving population.
The study employed a head -free eye tracking device to increase the realism of the driving
situation (no head - mounted gear). However, the eye tracker had a sampling rate of 60 Hz, which
made determining saccades problematic. The eye tracker and analyses software employed in this
effort represents a significant improvement in technology over previous similar efforts in this
area.
The study focused on objects that were 1,000 feet or less from the drivers. This was dictated by
the accuracy of the eye tracking system and the ability to resolve objects for data reduction. In
addition, the geometry of the roadway precluded the consideration of objects at great distances.
55
The study was performed on actual roadways, and this limited the control of the visual scenes
except via the route selection process. In an ideal case, one would have had roadways with
CEVMS, standard billboards, and no off - premise advertising and in which the context
surrounding digital and standard billboards did not differ. This was not the case in this study,
although such an exclusive environment would be inconsistent with the experience of most
drivers. This presents issues with the interpretation of the specific contributions made by
billboards and the environment to the driver's behavior.
Sign content was not investigated (or controlled) in the present study, but may be an important
factor to consider in future studies that investigate the distraction potential of advertising signs.
Investigations about the effect of content could potentially be performed in driving simulators
where this variable could be systematically controlled and manipulated.
56
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:1
Attachment "E"
CITY OF WINTER SPRINGS, FLORIDA
DRAFT MINUTES
PLANNING AND ZONING BOARD /LOCAL PLANNING AGENCY
REGULAR MEETING - JUNE 4, 2014
PAGE 4 OF 8
PUBLIC HEARINGS
501. Community Development Department — Planning Division
The Community Development Department — Planning Division Requests That The
Planning And Zoning Board Consider Ordinance 2014 -14 *, Which Proposes To
Amend The City's Regulations Regarding Off - Premises Signs, Commonly Referred
To As Billboards And Electronic Message Centers.
Note: This Ordinance should have been listed as Ordinance 2014 -13
Mr. Bobby Howell, AICP, Planner, Community Development Department explained that
the Ordinance deals with both Billboards and Electronic Message Centers, and presented
the Billboard aspect of the Ordinance.
Mr. Stevenson advised the Board that, "We are not talking about any additional billboard.
It's still just the two that are on (U.S.) 17 -92." Further comments.
Following, Mr. Steve Richart, Urban Beautification Division Services, Community
Development Department presented the Electronic Message Center aspect of the
Ordinance.
Much discussion ensued on the maximum square footage of the Electronic Message
Centers remaining the same; allowable speed settings, which are fairly universal;
government safety studies; and insurance company accident reports.
There was a concern that the two second interval will create flashing billboards in the
City. Mr. Richart stated, "Flashing is not allowed."
Further comments.
"I WOULD LIKE TO MOVE THAT ITEM `501' BY THE COMMUNITY
DEVELOPMENT DEPARTMENT ASKING TO CONSIDER ORDINANCE 2014-
13 BE APPROVED AS RECOMMENDED BY STAFF." MOTION BY BOARD
MEMBER POE. SECONDED BY BOARD MEMBER PHILLIPS. DISCUSSION.
Chairperson Henderson opened "Public Input ".
No one spoke.
Chairperson Henderson closed "Public Input ".
CITY OF WINTER SPRINGS, FLORIDA
DRAFT MINUTES
PLANNING AND ZONING BOARD /LOCAL PLANNING AGENCY
REGULAR MEETING - JUNE 4, 2014
PAGE 5 OF 8
VOTE:
VICE - CHAIRPERSON CASMAN: AYE
BOARD MEMBER POE: AYE
CHAIRPERSON HENDERSON: AYE
BOARD MEMBER PHILLIPS: AYE
MOTION CARRIED.
PUBLIC HEARINGS
502. Community Development Department — Planning Division
The Community Development Department — Planning Division Requests That The
Planning And Zoning Board Consider Ordinance 2014 -12, Which Proposes To
Amend Section 20 -431 Of The Code of Ordinances Regarding The Parking, Storage
Or Maintenance Of Recreational Vehicles, Boats And Boat Trailers In Residential
Zoning Districts.
Board Member Bart Phillips stated, "Before we begin this, I would like to exclude myself
from this discussion because I have a conflict."
Mr. Howell presented this Agenda Item, and explained, "After you got your packets,
Staff has had a chance to take a look at this Ordinance a little bit more in depth and there
are some changes that we are going to propose, that Mr. Stevenson would like to go over
with you."
Following, Mr. Stevenson explained the following, "Subsequent to this Agenda Item
being written, we've had additional conversations at the Staff level, involved the Police
Department a little bit more, and also the City Manager. As I've told this group before
we never want to write a section that is not enforceable in the field and we had some
language that we felt was a little bit weak, shall we say, and maybe some that may have
been regulated that we didn't want to regulate at this point."
Mr. Stevenson referred to Ordinance Number 2014 -12 and began, "Starting on page 2 of
4, under (1) Prohibitions: you have a section `f' that starts with `No recreational
vehicle'. I need to interject a sentence prior to that addresses the situation that we have in
a lot of cases today, and that sentence would say something to the following: `All RV's
and Boat Trailers with or without a boat thereon parked or stored in a residentially zoned
district shall be parked or stored behind the front building line.'
That is the case that exists today. We are drawing a line between those that have a Permit,
those that need to get a Permit, and those that don't need to get a Permit. All of them
have to be parked behind the front building line, which is the case today."
chment T"