Minnesota Department of Transportation Rural Intersection Conflict Warning System (RICWS) Reliability Evaluation

Abstract

The Minnesota Department of Transportation (MnDOT) developed the Rural Intersection Conflict Warning System (RICWS) Deployment project to reduce crashes at stop-controlled intersections. It is a statewide, Intelligent Transportation Systems project that will deploy intersection conflict warning systems at up to 50 rural, stop-controlled intersections. These systems will address crashes at stop-controlled intersections by providing drivers - on both the major and minor road - with a dynamic warning of other vehicles approaching the intersection. The first RICWS site, Trunk Highway 7 and Carver County CSAH 33, was evaluated for a period of 34 days to demonstrate the reliability of the system. During this period, the RICWS signs, beacons, and any other displays were covered and unavailable for driver interaction. The University of Minnesota installed a portable Intersection Surveillance System (ISS) and collected data from the RICWS as well as from the ISS. The data collected from the RICWS was validated against data recorded by the ISS in order to determine the accuracy and reliability of the RICWS. The RICWS was determined to have an activation rate of 99.98%, and meets the MnDOT specification of 99.95% sign activation rate. Sign activations were also validated using video captured at the site and a sample of times for valid activations and valid periods when the sign was inactive were recorded.