Infrastructure Collision-Avoidance Concept for Straight-Crossing-Path Crashes at Signalized Intersections

Abstract

Concepts to improve intersection safety with infrastructure-only and infrastructure-vehicle-cooperative collision-avoidance systems were assessed. These systems address straight-crossing-path crashes at signalized intersections. System components include sensors, processors, driver information devices, roadside-to-vehicle communication systems, and on-vehicle systems. The deployment model to realize infrastructure vehicle cooperation assumes the introduction of infrastructure-only systems that service all drivers with warnings provided by roadside information devices. These systems would be followed by the addition of roadside-to-vehicle communication systems that service drivers of intelligent vehicles through in-vehicle warnings. These concepts can be used to avoid a crash when a vehicle violates the signal. Equations of motion illustrate how a simple algorithm can be used to identify potential violators by using speed at a measurement point on the approach to an intersection. The example suggests that most potential signal violators can be warned in time to stop before they collide with a vehicle from the cross street. Analysis also indicates that when warnings of the possible signal violation are conveyed to drivers on the cross street, many of these drivers can also stop before colliding with the signal violator. In the example, 88% of the relevant straight-crossing-path crashes were addressed by providing timely warnings to either the violators or the other drivers. Deployment costs and benefits were estimated to demonstrate the potential value of infrastructure intersection collision-avoidance systems.