Non-Recurrent Congestion: Improvement of Time to Clear Incidents

The greatest benefit that freeway ITS can provide is to assist in the reduction of the time that it takes emergency responders to clear incidents and restore normal traffic operations. This chapter describes the ways that ITS can facilitate these operations and the benefits that result. Guidance for the field location of ITS components is provided. The chapter covers the following: Stages of an incident Effects of incident on roadway capacity and models of delay resulting from an incident Relationship of incident clearance time to delay Adaptation of delay models to local traffic data Design functions and technologies to assist in incident management CCTV coverage requirements and camera placement guidelines Traffic detector technologies and placement guidelines Improvement of traffic management center support of incident management Evaluation of incident management effectiveness