HomeMy WebLinkAbout2006 01 23 Regular Item 303 Sidewalks Dyson Drive
COMMISSION AGENDA
ITEM 303
REGULAR X
January 23,2006
Meeting
MGR / DEPT
Authorization
REQUEST: Public Works providing the City Commission the updated design drawings for the
proposed installation of sidewalks on Dyson Drive, and requesting that the
Commission set a date for a public meeting to present the design to the residents.
PURPOSE: The purpose of this agenda item is to provide the City Commission the updated design
drawings for the proposed installation of sidewalks on Dyson Drive, and requesting that the
Commission set a date for a public meeting to present the design to the residents.
PROJECT SUMMARY:
Seminole County has proposed the construction of five foot sidewalks along Dyson Drive. The County's
proposal is based on the recommendations of the Seminole County School Safety Advisory Committee,
which performed a sidewalk needs assessment of all arterial and collector roadways within two miles of
all County schools. The proposed sidewalk improvements would be funded through the County at a cost
savings to the City of approximately $850,000. The County has also indicated that funding is available
for traffic calming along Dyson Drive. The enclosed drawings show the updated sidewalk design and the
proposed traffic calming along Dyson Drive. The proposed sidewalks along the south side of Northern
Way and west side of Shetland Avenue are not part of this agenda item and will be brought back to the
Commission at a later date.
PROJECT STATUS AND PUBLIC FEEDBACK UPDATE:
At the June 27, 2005 City Commission meeting, the Commission directed staff to proceed with the
recommended design modifications. The modifications consist of adjustments to the sidewalk alignment
to improve pedestrian safety and minimize tree impacts. The design also incorporates traffic calming on
Dyson Drive.
Out of a total of 35 residents along the Dyson Drive corridor, 19 have provided input as of January 17,
2006, either through the public meeting held April 21, 2005, or by direct communication with Staff in
response to the various mailings that have been issued for the project. The results of the responses
received to-date are summarized as follows:
012306_ COMM _Regular _ 303 _Dyson Drive Sidewalks
Regular Agenda Item 303
January 23,2006
Page 2
Dyson
Drive
Total Residents 35
Total Responses Received 19
For 9
Against 7
Neutral 3
DESIGN MODIFICATION SUMMARY:
~ The Dyson Drive sidewalks have generally been moved away from the road closer to the edge of
the right-of-way. This location is best for pedestrian safety, aesthetics, and traffic calming, and it
is consistent with existing sidewalks throughout similar residential streets in Tuskawilla, such as
Northern Way, Tuscora Drive, Vistawilla Drive, Seneca Boulevard, and Howell Creek Drive.
When the sidewalks are located away from the street, it increases pedestrian comfort and creates
better conditions for having a "tree canopy," which has aesthetic appeal and provides traffic
calming.
~ Many residents have expressed concerns about the potential tree impacts due to the sidewalks.
The revised Dyson Drive sidewalks now meander in some areas to avoid impacts to trees and other
existing facilities. As a result of the modifications, only four (4) trees along Dyson Drive will
need to be removed, the largest of which is 8-inches in diameter. No trees will be removed along
Northern Way or Shetland Avenue. Some tree branch trimming will be required along all
segments to provide the necessary pedestrian clearance over the sidewalk.
~ Many residents also expressed concerns about speeding along the subject streets. The Dyson
Drive segment now includes traffic calming. The proposed traffic calming was designed by Metric
Engineering, based on recommendations by the County's traffic consultant (PBS&J) and the City's
traffic consultant (Ian Lockwood from Glatting Jackson). All three of these firms are nationally
recognized as highly reputable transportation engineering firms. The traffic calming consists of
mini-traffic circles at the intersections of Dyson Drive with Morgan Street and Pinto Court, and
the installation of median islands at various locations along Dyson Drive.
~ The mini-traffic circles are 16-foot diameter curbed circles located in the center of the intersection
(see drawings for details). The circles will be landscaped and will have appropriate signage and
striping to ensure safe operation for motorists and pedestrians. The mini-traffic circles have been
designed in accordance with the Seattle Guidelines, which are nationally recognized as the
industry standard for traffic circles. Over 600 similar traffic circles have been installed in the City
of Seattle as a part of their Neighborhood Traffic Calming Program. Traffic circles provide the
following benefits:
o Reduced vehicle speeds
o Reduced accident rates
o Popular with residents
o Make neighborhoods a safer and better place to live
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Regular Agenda Item 303
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~ Metric Engineering, along with City Staff, conducted field testing for the proposed traffic circles to
verify that the circles would safely operate as intended for large trucks. The testing consisted of
using cones to represent the traffic circles and then driving around each circle counterclockwise in
a large single-unit truck. The field testing showed that the circles could safely accommodate large
single-unit trucks. As with most traffic circles, tractor-trailers have to use caution when making
left turns, as they will likely need to make immediate left turns rather than proceeding
counterclockwise around the circle as all other vehicles would.
~ The proposed median islands consist of 6- foot wide curbed medians with lengths up to 40- feet
located in the center of the road. The medians will be landscaped with ground cover and relatively
short vegetation. Approximately eight (8) medians are proposed at various locations along Dyson
Drive. The medians do not block access to any driveways or intersections, and they will be striped
and reflectorized to clearly identify them to motorists. The medians help calm the traffic in two
ways. First, the medians reduce unobstructed roadway sight lines that contribute to speeding.
Second, the medians reduce lane widths (in this case from 12-feet to 9-feet), which also helps to
slow vehicles down. The medians work in tandem with the traffic circles and are the best means
of calming the traffic on Dyson Drive given the constraints of the existing roadway.
~ Several residents have asked for stop signs to be installed at the Dyson Drive intersections. This is
not recommended, as stop signs are not considered to be effective traffic calming devices. Stop
signs only slow vehicles down in the immediate vicinity of intersections, whereas traffic circles are
part of a series of devices along the entire corridor that collectively create an environment less
favorable to speeding. Also, the installation of unwarranted stop signs along collector streets like
Dyson Drive creates additional public safety concerns, as drivers along the major street (in this
case Dyson) tend to run or roll through stop signs when traffic volumes on the minor streets are
very low.
~ Several residents have expressed concerns about the potential impact of the sidewalks on drainage.
The proposed sidewalks will not have any impact on the existing drainage patterns. Dyson Drive,
generally has a swale drainage system. The swales are located adjacent to the road and are
designed to collect runoff from the roads and the adjacent properties. The proposed sidewalks are
located on the property side of the swales, several feet above the swale bottom in most cases, and
the at-grade sidewalks will not prevent runoff from reaching the swales. Staffhas observed in this
area that heavy storms leave standing water in the swales and in driveways in several locations
where the driveways follow the swale grades. This standing water is expected and is normal for a
swale drainage system, at least for up to 72 hours after major storms. It is the only means of
stormwater retention in this area and this is an important part of the stormwater management
system. After major storm events, some areas have more standing water than others, and this is
understandably a nuisance to the affected residents.
RECOMMENDATION:
It is recommended that the City Commission review the plans and set a public hearing date. The
Commission may wish to consider conducting a referendum on this project.
o 12306_COMM_Regular_303_Dyson Drive Sidewalks
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IMPLEMENTATION SCHEDULE:
Seminole County has programmed funding for the project and is waiting on a commitment from the City
before proceeding.
ATTACHMENTS:
1. Dyson Drive design drawings prepared by Metric Engineering
COMMISSION ACTION:
Ol2306_COMM_Regular_303_Dyson Drive Sidewalks
SEMINOLE COUNTY GOVERNMENT
PUBLIC WORKS DEPARTMENT
ENGINEERING DIVISION
PROPOSED PLANS FOR
DYSON DRIVE
SIDEWALK CONSTRUCTION
HOWELL CREEK TO SHETLAND AVE
TREE SIDEWALK DETAIL
HANDRAIL DETAIL
GRAVITY WALL DETAIL
TREE ROOT AVOIDANCE DETAIL
HANDRAIL DETAIL WITH GRAVITY WALL DETAIL
STA 266-84 TO STA 267-04(LT)
MEDIAN ISLAND DETAIL
PLAN VIEW
TYPICAL SECTION AND DETAILS
TRAFFIC CIRCLE
PLAN VIEW
TYPICAL SECTION AND DETAILS
TRAFFIC CIRCLE
MEDIAN ISLAND DETAIL
PLAN VIEW
TYPICAL SECTION AND DETAILS
SIDEWALK PLAN
STA 228+00.00 TO STA 233+60.00
SIDEWALK PLAN
STA 233+60.00 TO STA 239+20
SIDEWALK PLAN
STA 239+20 TO STA 244+80
SIDEWALK PLAN
STA 244+80 TO STA 250+40
SIDEWALK PLAN
STA 250+40 TO 256.00
SIDEWALK PLAN
STA 256+00 TO STA 261+60
SIDEWALK PLAN
STA 261+60 TO STA 267+20
SIDEWALK PLAN
STA 267+20 TO STA 272+80
SIDEWALK PLAN
STA 272+80 TO STA 278+40
SIDEWALK PLAN
STA 278+40 TO STA 284+72