Public Service recommends maintaining duration of amber lights of four seconds
Released: 10:01 a.m.
NEWS @ A GLANCE:
Today, the Public Service recommends maintaining the current practice of having four seconds of amber light time and adopting a formula to calculate the all-red light time, as this provides a safer scenario than having a longer amber light time. (for more details, please read the full media release below)
WINNIPEG - March 8, 2011 - Today, the Public Service recommends maintaining the current practice of having four seconds of amber light time and adopting a formula to calculate the all-red light time, as this provides a safer scenario than having a longer amber light time.
On September 15, 2010, the Executive Policy Committee directed the Public Service to review the State of Georgia legislation, which required amber lights at signalized intersections to be timed to United States federal engineering standards, plus one additional second; as well as any other relevant studies or legislation regarding the effect of longer yellow lights on intersection safety.
"After reviewing State of Georgia legislation and City data, we have found that there is no demonstrated benefit to increasing amber light times by one second," said Luis Escobar, the City's Manager of Transportation.
"If we were to use the same method for calculating amber times as they do in Georgia, it could actually result in some intersections having shorter amber durations than the four seconds we currently use," said Escobar. "While motorists running red lights can be an indication that amber durations are too short, data from Winnipeg's photo enforced intersections has shown that there is a very low percentage of motorists being ticketed at these intersections."
The report states that amber light times of four seconds are suitable for Winnipeg roads with speeds up to and including 80 km/h and are within acceptable engineering practices.
Furthermore, the report states that the duration of amber intervals alone is not always adequate to help reduce collisions. In Winnipeg, additional time is already provided based on engineering judgment to improve the safe operation of a signalized intersection. This is done through the use of an all-red interval, to prevent a motorist on the side street from entering an intersection when a motorist on the main road may still be inside the intersection. This all-red interval varies between zero and three seconds and is based on the characteristics of each intersection. When adding both the amber and all-red intervals together, we end up with clearance intervals between four seconds (when no all-red is used) to up to seven seconds (when we include three seconds of all-red).
Since photo enforcement and traffic signals timing practices in Winnipeg are based on the concept of violation on entrance rather than violation on exit, it can be concluded that the results of these studies, while informative, do not provide any useful information related to whether or not there is a need to modify the current duration of amber intervals in Winnipeg.
The report also recommends incorporating the use of the Institute of Transportation Engineers' equation to supplement the City's current process for estimating all-red light times.
The report will go forward to the Standing Policy Committee on Infrastructure Renewal and Public Works on March 15, 2011.