Event-Based Framework for Noncompliant Driver Behavior at Single-Lane Roundabouts

Roundabouts are an emerging form of intersection control in the United States. The nature of roundabouts, requiring drivers to yield at entry, promotes a level of road user responsibility higher than that at inter sections with other types of control. This research addresses current roundabout modeling and analysis methods by focusing on the types of driver behavior that are not gap acceptance–based, do not follow the offside priority rule, are interactive between traffic streams, and have unique effects on roundabout performance. A new framework for describing priority-taking, priority-abstaining, and priority-surrendering behavior at roundabouts is presented; a reduction methodology for the extraction of these types of behavior from video is described. The findings suggest that these noncompliant driver behaviors are, prevalent, may significantly affect roundabout performance, and remain unaccounted for in current modeling approaches. Furthermore, the results indicate that frequency of priority-taking behavior remains constant, whereas priority-abstaining behavior diminishes with time since construction of a roundabout.