Road Incidents and Network Dynamics

Abstract

Incidents cause a large part of the congestion on the road. This PhD study describes how people change their behaviour when facing an incident situation. It is found that car-following behaviour changes and drivers react slower on their predecessors. Furthermore, it is found that drivers change their route when facing unexpected delay caused by an incident. The route choice if the queue is caused by an incident is different from the situation with a similar queue which is not caused by an incident. Also the queuing patterns in the network are studied. It is found that so called “spillback” effects are important. This is a queue with cars heading to a direction with a bottleneck which blocks the cars to another direction, which do not need to pass the bottleneck. Due to these effects, it is essential to use an accurate representation of traffic when calculating the total delays of an incident. The findings of this thesis can be used for creating more robust road networks, causing less delay in case of incidents.