Center for Transportation Research and Education

About the research

Winter weather and its corresponding surface conditions impact the safety and mobility of thousands of motorists annually. Highway agencies spend millions of dollars in resources and personnel in an effort to ensure safe and efficient travel. One such strategy is to use dynamic message signs (DMS) that have been deployed across the state to alert drivers of conditions ahead based on data from roadside sensors. This type of advisory system can provide real-time information, allowing drivers to adjust their driving behavior to the conditions ahead.

The objective of this project was to analyze traffic behavior along a specially instrumented portion of the US 12 corridor under various winter weather conditions when advisory messages triggered by roadside pavement sensors were provided via DMSs between Delano and Maple Plain, Minnesota. Temporary traffic sensor data upstream and downstream of the DMS are used to evaluate traffic flow metrics during winter weather conditions as compared to baseline conditions.

In the eastbound direction, statistically significant reductions in mean and 85th percentile speeds of 3.5 mph and 2.9 mph, respectively, were identified. The westbound direction experienced mixed results, with a mixture of statistically insignificant changes as well as statistically significant increases and decreases in speeds. It is assumed that other factors were influencing driver behavior in this westbound direction. There were indications of positive effects on vehicle gaps when evaluating all events combined that were statistically significant but not when evaluating individual winter weather events.