About the research
The Minnesota Department of Transportation (MnDOT) is investing significant resources in intersection collision warning systems (ICWS) based on early indications of effectiveness. However, the effectiveness is not well documented, and negative changes in driver behavior at treatment intersections may affect drivers overall, resulting in a spillover effect. Moreover, the effectiveness of ICWS may decrease if drivers do not perceive a change in the dynamic messages. Therefore, the objectives of this research were to (1) evaluate driver behavior at mainline and stop-controlled approaches for intersections with and without ICWS and (2) assess the traffic volume range and limits where the system is nearly continuously activated and is likely to lose its effectiveness.
Video data were collected at five treatment and corresponding control intersections, and various metrics were used to compare changes in driver behavior. In general, no negative behaviors were noted for either treatment or control intersections.