Research On Dynamic Traffic Assignment Model Based On Heuristic Algorithms

With the continuous development of the economic and expansion of the urban transport network, citytraffic congestion, traffic safety and other issues have spread worldwide,people start to consider how toreasonably distribute the traffic flow. Under this condition,the distribution model of traffic flow hasemerged. Conventional traffic assignment model almost is static model,and don’t consider the real-timechanges.Because the equilibrium assignmentmodel has large number of variables and restriction conditions,the model is difficult to solve.In order to solve this problem, people put forward many algorithms.But these algorithms cannotactually simulate the process which the vehicles select the path.Basing on the probability shiftingideological of the ant colony algorithm,this paper researchs and builds the dynamic traffic assignmentproblem. The specific work is list as follows:1. Two of the dynamic traffic assignment model have been analysed, they are the system optimalassignment model and the user optimal assignment model. It conduct experimental studies on some of theant colony optimization algorithm, like EAS、ASrank、ACS.2. With transforming the dynamic traffic system optimal allocation problem into a0-1integerprogramming problem，dynamic traffic user optimal problem turn into a nonlinear programming problem.It respectively use the0-1programming and nonlinear programming method to realize the dynamic trafficsystem optimal distribution and dynamic user optimum traffic distribution and prove the feasibility of theDSO model and DUO model.3. The probability shifting ideological of the ant colony algorithm has been introduced into the thesolution of the dynamic traffic assignment model. It respectively built the dynamic system optimal trafficdistribution model and dynamic user optimum traffic distribution model with the ACS algorithm. The testresult show that compared with the corresponding traditional distribution, the solution of the dynamicfraffic assignment model which is proposed in this paper has the better permformance on the trafficdistribution and the solving optimal impedance.