A review of western Canada's traffic signal clearance interval practices.

This paper presents a review of the current practices for determining vehicle clearance intervals at signalized intersections in Western Canada. The paper has been prepared to provide international input into the ITE Traffic Signal Timing Advisory Committee (TSTAC). One of TSTAC's objectives is to develop a "recommended practice" for the determination of yellow and all-red vehicle clearance intervals at a traffic signal. Provincial statutes and regulations governing actions required by motorists approaching yellow and red displays at traffic signals in the Provinces of British Columbia, Alberta, Saskatchewan and Manitoba are examined. Procedures for establishing yellow and red clearance interval durations are summarized, for signals under provincial jurisdictions and the jurisdictions of major municipalities. An analysis of the correlation between the legislation and practices is provided.