The Saskatchewan Ministry of Highways and Infrastructure (the Ministry) completed a study in 2015 to expand their compliment of safety countermeasures along medium to high volume corridors and
intersections. The report recommended to only consider the implementation of traffic signals where
certain operational and safety conditions were met. The Ministry has not traditionally used signals at isolated, high speed rural intersection as a safety countermeasure because of the risk that collision severity will increase, in addition to compromising the intended mobility of these free-flowing major highway systems.
Within this context, the Ministry retained Tetra Tech to assist in the development of policies and
procedures for signal adoption. The policies will guide the Ministry to determine whether traffic
conditions are/are not favourable to support signal implementation at locations under review. Policy
statements were developed from current industry practices and from other jurisdictions’ guidelines and policy documents. A total of 13 statements were recommended to address: conditions where traffic signals could be considered, conditions where they may not be appropriate and other policy decision items.
The current procedures adopted by the Ministry date back to 1989, and followed closely to the
Transportation Association of Canada (TAC) guidelines of that time. As part of this latest initiative, Tetra Tech reviewed the current TAC procedures as well as other industry practices to confirm the approach that should be adopted that represents the Saskatchewan context. The recommendation for the Ministry was to adopt a hybrid of approaches used in North America jurisdictions that address the following:
Achieving a minimum traffic volume for various time periods (eight-hour, four-hour and peak-hour
volumes);
Meeting a specific collision experience threshold that demonstrates under certain conditions, installing signals can benefit an intersection by reducing collisions of a high severity and type sufficiently to offset the increase in similar/lower severity collisions;
Coordinated signal system to address adequate progression of vehicles along the main corridor; and
Demonstrated improvement in the level of service and delay.
This paper will present a summary of current industry practices, to discuss the establishment of policies and preferred warrants for adoption by the Ministry, as well as to provide the findings of a calibration check that applied the recommended policy statements and warrant procedures on four candidate intersections.
