HomeMy WebLinkAboutSS3 - Battery Back-Up for Traffic SignalsJune 26, 2001
STUDY SESSION
ITEM NO. ss3
TO: Mayor and Members of the City Council
FROM: Public Works Department
SUBJECT: BATTERY BACK -UP FOR TRAFFIC SIGNALS
DISCUSSION:
The uncertainty of the supply of electrical power has created interest in back -up battery
systems to run traffic signals during a power outage. The vehicle code states that a
non - operational signal is to be treated as a STOP sign, however, many motorists are
either unaware of this or choose to ignore this law. The City Attorney's office does not
believe there is liability to the City for a signal that is non - operational due to a power
outage and our Police Department has established a response procedure to deal with
rolling blackouts.
Several companies supply these back -up power systems in various configurations
depending upon required operating parameters including the number of signal heads,
the length of time the back -up is required, and whether the signal is to operate in normal
fashion or only in a flashing red mode. These systems require the use of LED signal
heads for both the red and green indications if full operation is to be provided. Some
systems fit into the existing signal cabinets while others require a separate cabinet due
to their size.
Flashing red operation is better understood than a non - operational signal and would
provide increased safety at a modest cost. Battery back -up capable of running the
signal in normal operation is more expensive, but there would be no congestion
resulting from a power outage. Traffic Engineering Staff consulted with the Police
Department and they support either back -up option. Even the flashing red option would
reduce manpower demands on officers during rolling blackouts.
Thirty -five intersections in the City are operated by Caltrans and many of them are at
key locations. These intersections are along Coast Highway, Newport Boulevard, the
Bristol Street Couplet, and three off ramps from Route 73. Caltrans has converted all of
the indications at signals along Coast Highway to LED and is looking into installing a
limited number of back -up power systems in the county this summer. Caltrans told Staff
they expect to convert all their intersections to LED's and install back -up power at all
locations within the next year, if they receive adequate funding. They cannot provide a
schedule specifically showing when any intersections in Newport Beach will have back-
up power. They have advised us that if we want to install back -up systems at their
intersections, they will return those to the City at such time as they install systems of
their own.
SUBJECT: BATTERY BACK -UP FOR TRAFFIC SIGNALS
June 26. 2001
Page 2
The cost of a back -up power system to provide flashing red operation is $3500 per
intersection. These systems can be installed in 4 to 6 weeks from the order date. To
provide full operation, including the conversion to green LED's, will cost $8000 per
location. The supply of green LED's is limited and it is expected to take 8 to 10 weeks
to complete these installations.
With seventy -five City- operated and thirty -five Caltrans- operated intersections, the cost
to provide full operation systems at all locations is quite substantial and would likely
exceed $700,000 including the cost to install green LED's, where needed.
To implement the Pilot Program, it is recommended that $100,000 be allocated to
provide full operation at 8 to 10 of the key intersections and flashing red operation at
another 8 to 10 intersections. Based upon traffic volumes and speeds on arterials
throughout the City, Staff believes the greatest benefit would result from placing
approximately half of the back -up systems at State - operated intersections. The specific
locations would be established jointly by the Public Works and Police Departments- The
Pilot Program Exhibit shows candidate intersections that could be provided with back -up
power for approximately $100,000. As mentioned above, the State will return the
systems to us once they install their own back -up power and we could then relocate our
units to other intersections.
Staff seeks direction from the City Council on whether or not to pursue a Pilot Program
of battery back -up power systems for traffic signals. The timetable for installation will
depend upon both product and contractor availability as many agencies are making
similar decisions at this time.
If the City Council desires to proceed with this program a budget amendment will be
prepared for the July 10, 2001, meeting to appropriate $100,000 from the Circulation
and Transportation Fund for the Pilot Program shown on the attached Exhibit. The
revenue for the Circulation and Transportation Fund is derived from Fair Share Fees
and the Fund balance can cover this expenditure.
Respe Ily su m' d
P WORKS DEPARTMENT
Don Webb, Director
By:
Richard M. Edmonston, P.E.
Transportation and Development Services Manager
Attachment: Pilot Program Exhibit
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