The Application Research On Reliability Of Route Travel Time And Its Distritution In The Aspect Of Traffic

The travel time reliability is a new index not only in the network design of road but also in the course of designing a new road. Besides, it also can be used in traffic assignment so as to guide the travel better than before. Based on the former study on the reliability of road network and the related research, the following three study aspects are carried out in this paper.Firstly, based on the basic framework of road network study and the evaluation rules of road network reliability, the paper emphasizes on analyzing three main aspects of road network reliability, which are connecting reliability, travel time reliability and capacity reliability. The key term of travel time reliability is expounded. Under corresponding assumptions, link travel time reliability is calculated and further extended to the calculation of route travel time reliability.Secondly, based on users'equilibrium (UE) assignment model, link travel time reliability is considered as traffic impedance in the assignment model of reliability. The link reliability takes the place of the function of travel fee; that is all the road users know the condition of the network and they try to choose the most reliable route. When the condition of road network come to the state of equilibrium, all used routes between every OD have the same and the maximum reliability and the reliability of routes not being used is less or equal to the maximum reliability. The model can reasonably reflect traffic assignment which has elastic demand.Finally, actual road network is applied to validate the calculation of travel time reliability and the above traffic assignment method.