Five-year study finds traffic signal priority helped reduce driving time by more than 20 percent, resulting in significant fuel savings.

October 29, 2020 (ST. PAUL, Minn.) – For decades, Opticom™ priority control has been utilized by cities for emergency vehicle preemption (EVP) and transit signal priority (TSP). But a five-year study by one snowy Minnesota city has proved its value goes beyond just those two use cases.

The city of St. Cloud, Minnesota gets an average of four feet of snow every year. Since most of its citizens get around by vehicle, the performance of the public works department – and in particular, snowplowing – is crucial.

In St. Cloud, police and fire have had EVP and the buses have had TSP for years. Five years ago, the city received an exemption from the Minnesota Department of Transportation (MDOT) to do an extensive study of Opticom for snowplows. Leveraging its existing intersection infrastructure, the pilot tested relative priority on four snowplows at seven intersections over a period of five years.

“Minnesota has recorded snowfall in every month but July, so plowing snow effectively is obviously critical here,” Traffic System Manager Blake Redfield said. “But little was known about how well the technology would function or what efficiencies and safety benefits might be gained by its use with snowplows.”

During the pilot, St. Cloud’s public works department collected data and turned it over to David H. Robinson, a Professor of Statistics at St. Cloud State University, along with a trio of grad students, to do an unbiased analysis of that data. They analyzed four years of snowplow data to determine the effects of Opticom priority control on snowplow efficiency.

Ultimately, the study found that routes with Opticom were plowed 4.25 minutes faster than those without Opticom, a driving time savings of 22 percent. As they wrote in their conclusion, “Relative Priority Preemption has a great future for the roadway maintenance world and should become part of the traffic signal infrastructure for every agency that operates traffic signals.”

“This study demonstrates the value and utility of priority control,” GTT Product Management Director Chad Mack said.

“The cities that are finding creative ways to leverage their existing infrastructure are the ones coming out ahead.”

A detailed case study of the St. Cloud snowplow pilot program can be found on GTT’s website.


About Global Traffic Technologies

GTT provides a clear path to smarter and safer mobility for communities worldwide. GTT’s Opticom intelligent transportation solutions help to increase safety, minimize traffic congestion and reduce greenhouse gas emissions, while maximizing resource efficiency and performance. Thousands of emergency, transit and traffic agencies have trusted the innovative, comprehensive Opticom traffic solutions for more than 50 years. Headquartered in St. Paul, Minnesota, GTT is the market leader in traffic management systems, having an installed base of more than 180,000 connected devices in over 3,100 municipalities worldwide, including 41 of the 50 largest U.S. cities.