Study On Spread Regular Of The Traffic Accidents And Diversion Measures In Expressway

Expressway has become an integral part of national transportation network to its safe, efficient and comfortable driving environment. In recent years, with the continuous development of social economy, there has been a significant increase of vehicle fleet, and the development of expressway is slower relatively. In expressway, the traffic flow can be great, so the accident will affect the whole road network. Thus, to study and analyze the regular pattern of traffic accident influence has a great significance in improving road management and guarantee the safety and reliability of road network.For the above, the characters in traffic flow change under accident conditions and accident spread dissipation`s critical factors have been studied and analyzed. The implied vehicle operation situation in accident effect areas has also been analyzed. The vehicle delay has been obtained and the embodiments of diversion support measure has also been carried out.This paper is based on Traffic Wave Theory, analyzed the accident duration and congestion propagation and dissipation, obtained the accident propagation model in expressway. Then analyzed the traffic speed in different traffic flow based on the research above, obtained the vehicle velocity distribution under accident influence, carried out the factors toward bypass measures. At last, the congestion dealing measures have been analyzed, three critical parameters effecting diversion measures have been carried out, and the exact formula of shunt size and the beginning and ending time of diversion has been obtained based on the delay calculation model. Also, the method of finding optimal classification path in Ant Colony Algorithm has been discussed, obtained the specific embodiments of diversion support measures based on all aspects.