Request #1445
Inspection/calibration records for the traffic signal controller located at Trask and Harbor for October 2013 through November 2014. Any traffic survey done after July, 21, 2008, if any, for Trask between Brookhurst and Harbor boulevards. Thank you.
Correspondence
Dear Mr. McMillan,
While the City does perform routine preventive maintenance at the traffic signal cabinet, the traffic signal controller does not require any type of routine calibration/inspection, therefore there are no records responsive to this request.
Sincerely,
Denise Kehn
Records Specialist
City of Garden Grove
714-741-5036
My request had two components, and the response answers only one, I still need the "inspection/calibration" requested. Thank you.
McMillan
Dear Mr. McMillan,
Attached is the information you requested regarding the traffic signal controller located at Trask Avenue and Harbor Blvd. Please click on the link below to access your documents.
Sincerely,
Denise Kehn
Records Specialist
City of Garden Grove
714-741-5036
Dear Mr. McMillan,
The following information has been provided by the City of Garden Grove's Traffic and Engineering Division:
A traffic signal is comprised of basically 3 components, controller, signal lights, and detection devices. The controller is the "brains" of the intersection. All the timing is inputted into the controller. This comprises of, but not limited to, the red, yellow, and green times, pedestrian timing, and the configuration of the directional phases. The controller sends output signals to all the signal lights per the configuration assigned to each direction. Each directional phase time is counted down in the controller to ensure that each light receives the programmed timing.
There is also a unit called the Malfunction Monitoring Unit (MMU) that monitors the activity at the intersection. The MMU ensures that conflicting phases do not come on at the same time, it monitors voltage drops and spikes at each signal head, and ensures that each phase receives at least the minimum required amount of time programmed in the MMU. If the MMU detects any of these activities are not functioning properly, it will put the signal in all red flash operation until a technician resolves the issue and resets the conflict monitor.
I hope this additional information is helpful.
Sincerely,
Denise Kehn
Records Specialist
City of Garden Grove
714-741-5036
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Dear Ms. Kehn:
Thank you for your prompt response. How does the City determine whether the "phase timing" of a traffic controller is actually operating as "programed"?
Richard McMillan