Snowplow Relative Priority Preemption Status: CompleteReport Date: 07/06/2020 Summary: The City of St. Cloud received a small grant from the Minnesota Local Road Research Board's OPERA Program to evaluate a new level of traffic-signal preemption for snowplows and similar equipment called relative priority preemption (RPP). Four snowplows at the St. Cloud central maintenance facility were equipped with combination GPS and video cameras. The city conducted an evaluation of the RPP system with the preemption system activated for a group of plows during selected plowing runs. Travel times from each snowplow operating together as a platoon were compared with and without the relative priority system. Five years of data showed that travel times for snowplows improved by 22 percent using relative priority preemption technology. In addition, the system provided many safety and operational benefits, such as reducing the number of unplowed snow windrows blocking cross-traffic at intersections and more quickly clearing the way for emergency vehicles during snowstorms. Final Deliverables: Report #OPERA20-01 Related Materials: Traffic Signal Preemption for Snowplows - (Brochure/Handout) Related Research: