Multiobjective-Based User Equilibrium And Road Pricing Strategies For A Bimodal Transportation Network

With the rapid growth of traffic demand and vehicle traffic,urban traffic problem has become a problem that China’s large cities have to face,and congestion is the most typical traffic problem.Traffic congestion leads to a series of problems such as low travel efficiency and increased exhaust emissions.Road pricing,as an economic means of traffic demand management,can adjust traffic demand and optimize travel structure,and has become a widely used method to alleviate traffic congestion in various cities and regions.However,the formulation of road pricing policy is of high complexity.It requires not only a clear understanding of travelers’ travel decisions,but also consideration of different system objectives.The revenue generated by road pricing also needs to be properly used and distributed.In view of trafic congestion,this paper first discusses the mode choice and route choice with multiple objectives from the perspective of travelers,and then studies the road pricing policy formulation with multiple objectives from the perspective of traffic managers.Firstly,this paper summarizes and analyzes the development status of the traffic assignment model,and emphatically introduces the multi-objective user equilibrium theory,including the common objectives of travelers and processing methods.On the other hand,it also summarizes the common system objectives,common road pricing schemes and the income distribution mechanism of road pricingIn the automobile and subway networks,this paper considers three attributes,including travel time,time reliability and travel cost,and analyzes the traveler’s mode choice and path choice behavior through the concept of travel time budget surplus.In addition,a multi-objective network equilibrium model of the bimodal network is established,and a path-based algorithm is put forward to solve the equilibrium model.Experimental results verify the validity of the m odel and algorithm.After the detailed analysis of the traveler’s travel decision,this paper puts forward a bi-level programming of road pricing from the perspective of sustainable development,and proposes to take advantage of the revenue of road pricing to improve the headway of subway.The upper level represents transportation managers,and considers multiple system objectives,namely economic sustainability,environmental sustainability and social sustainability.The lower level represents travelers,who make their travel choice under the road pricing policy.This paper also combines the multi-objective genetic algorithm(NSGA-Ⅱ)and path-based assignment algorithm to solve the bi-level programming effectively.