HomeMy WebLinkAbout2012-02-15 PACKET 04.I.REQUEST OF CITY COUNCIL ACTION COUNCIL AGENDA
MEETING ITEM #
DATE 2/15/12 m
PREPARED BY Engineering Jennifer Levitt
ORIGINATING DEPARTMENT STAFF AUTHOR
COUNCIL ACTION REQUEST
Approve the proposal dated February 6 2012 from S.E.H. for the operational review of the
seven traffic signals under the city's jurisdiction.
STAFF RECOMMENDATION
It is recommended the Council approves the proposal dated February 6 2012 from S.E.H. for
the operational review of the seven traffic signals under the city's jurisdiction.
BUDGET IMPLICATION $12,100
BUDGETED AMOUNT ACTUAL AMOUNT
ADVISORY COMMISSION ACTION
❑ PLANNING
❑ PUBLIC SAFETY
❑ PUBLIC WORKS
❑ PARKS AND RECREATION
❑ HUMAN SERVICES /RIGHTS
❑ ECONOMIC DEV. AUTHORITY
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SUPPORTING DOCUMENTS
DATE REVIEWED
APPROVED
DENIED
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® MEMO /LETTER: Jennifer Levitt, February 8, 2012
❑ RESOLUTION:
❑ ORDINANCE:
❑ ENGINEERING RECOMMENDATION:
❑ LEGAL RECOMMENDATION:
❑ OTHER:
ADMINISTRATORS COMMENTS 1
a is
City Administrator Date
COUNCIL ACTION TAKEN: ❑ APPROVED ❑ DENIED ❑ OTHER
HACOUNCIL FORMS \Council 2 -15 -12 \Council Action Form SEH traffic signals review.doc
CITY OF COTTAGE GROVE
J MINNESOTA
To: Honorable Mayor and City Council
Ryan Schroeder, City Administrator
From: Jennifer M. Levitt, P.E., City Engineer
Date: February 8, 2012
Re: Approve Traffic Signal Proposal
Background /Discussion
Traffic signals are an important factor in moving traffic efficiently and effectively on roadways.
Traffic signal timing is the key to enable that movement and eliminate the frustrating wait times
at signals. There can be a lot of energy consumed by idling vehicles at traffic signals.
According to the Institute of Transportation Engineers, "There are about 300,000 traffic signals
in the United States alone and over 75% of them could be improved by updating equipment or
adjusting the timing. Traffic signal retiming is one of the most cost - effective ways to improve
traffic movement and make our streets safer. Comprehensive signal retiming programs have
documented benefits of 7 -13% reduction in overall travel time, 15 -37% reduction in delay and
a 6 -9% fuel savings.
Signal timing is the process of optimizing the operations of signalized intersections. The
objective of signal timing is to respond to the demands of all types of motor vehicles, bicycles
and pedestrians in an optimal manner. Signal timing strategies include the minimization of
stops and delays, fuel consumption and air pollution emissions and maximizing progression
along an arterial.
Signal timing is only effective as long as the traffic patterns that were used to generate the
signal timing remain reasonably similar. However, over time, traffic patterns change. Signal
retiming should be reviewed every year to evaluate its effectiveness and to make any changes
necessary."
Many agencies have their signal timing review on a 5 year cycle, which enables them to adjust
for changes in traffic patterns and traffic volume changes. The City of Cottage Grove has not
completed a system wide review of the traffic signals before. So the need for a complete
review of the operations of the existing traffic signals is very important. It is anticipated that the
state will be reviewing and developing new signal plans for the traffic signal operation at the
three signals in Cottage Grove in 2012 under their jurisdiction. This will provide for a
coordinated signal system for the City. The enclosed proposal outlines the scope of work for
the system review for the seven signals under the city's jurisdiction.
• Data Collection /System Review
o Turning movement counts will be collected at each intersection for 13 continuous
hours (Tuesday, Wednesday, or Thursday).
• As a cost savings measure a temporary video system will be installed, instead of
having an individual sifting at the intersection.
• Review plans for the signals and conduct a field audit of the control equipment.
• Timing Plan Development
• Create a computer model, Synchro to develop new timing plans.
• New guide lines were developed by the 2009 Manual on Uniform Traffic Control
Devices, the signals will be review for conformance of these guides. This is an
important element to reduce the city's liability.
• The revised timing will be analyzed to find the most efficient timing plan.
• Timing Plan Implementation
• The new timing plans will be set up in each controller.
• Review operations of new timing.
• Coordinate with the city's maintenance provider, City of St. Paul, for new timing
and operations.
It is staff's recommendation to conduct a system wide review of the signal operations with
S.E.H. for the total fee not to exceed $12,100.
Recommendation
Approve the proposal dated February 6, 2012 from S.E.H. for the operational review of the
seven traffic signals under the City's jurisdiction.