Traffic Diversion Method of Regional Highway Network after Unexpected Traffic Incident

Unexpected traffic incident which occurs in regional highway network brings about accidental congestion easily. It can also induce second traffic incident. So it affects the normal operation of the regional transportation seriously. The fundamental solution is to diverge the traffic flow upstream the incident point. Therefore, a diversion method which bases on Incremental Allocation Method has been developed. The method is composed of the determining of diversion range, the origins-destinations (O-Ds) and their diversion volumes, the modified Incremental Allocation Method and the modified Impedance Function. They ensure the feasibility and broad applicability of the method. Because the method of expanding the diversion range is considered in the method, so it can solve the diversion problem in much larger scale highway network. Example results show that the method can realize the rapid diversion of the traffic flow upstream the incident point going to surrounding roads. The traffic pressure of the incident link is effectively alleviated. So much more time and space are saved for the incident handling, and the socio-economic impacts are reduced.