Research On Traffic Network Equilibrium And Choice Of Travel Mode Based On Travel Credits Scheme

The travel credits scheme is a novel form and method for transportation demand management, which is introduced to alleviate the problem of urban traffic congestion.The significance of research about travel credits and previous studies on travel credits are summarized in this thesis, then a literature review on travel credits scheme focusing both on domestic and international field is presented. Based on theory researches, the main research purposes and contents are proposed. This thesis contains the following main four parts:(1) The theoretical basis of the travel credits scheme is detailed collated and summarized. Based on the conceptual research of the travel credits scheme, the three main contents about implementation process of travel credits scheme are discussed. The user equilibrium model considering the travel credits scheme, the equivalent mathematical programming model and the related theoretical properties are sorted out and summarized.Finally, from the perspective of urban traffic congestion, the economic principles of the travel credits scheme and the reasons for the impact of the travel credits scheme on the individual travel are analyzed, which lay the theoretical foundation for the later researches.(2) Study on the travel credits scheme considering perceived cost under elastic demand. Considering that if the route charges more credits than initial distribution, a perceived error cost is generated, which leads to more generalized travel cost, taking into consideration link travel time cost, travel credits cost and perceived cost three parts as generalized travel cost. We propose the network equilibrium and market equilibrium (ME)conditions considering perceived error cost, and a variational inequality (VI) model is proved same to network equilibrium-ME conditions. According to the characteristics of the model, the adaptive step size algorithm is used to solve the model and the examples are validated on two networks. The study shows that occurrence of perceived error costs may cause the distortion of traffic distribution in the road network and the decrease of the efficiency of the travel credits scheme.(3) Study on travel assignment under travel credits scheme considering variation of link travel time. Due to changes in traffic environment those maybe cause the link travel time fluctuations, and the drivers can perceive the reduction of the traffic capacity. In this chapter, own to the disturbance of the external factors the capacity of link will lost, which leads to changes of link travel time, and a link travel time considering degraded parameter is built. Therefore, the generalized travel cost includes the travel time considering the time variation and the travel credits cost. The network equilibrium and market equilibrium conditions considering variation of link travel time are formulated into a variational inequality (VI) problem. Analyses demonstrate that with the more negative factors influence on road network the more travel time need by travelers.(4) Study on the choice of travel mode under travel credits scheme. In a city where both private cars and public transport are considered, the traveler's travel utility changes due to the implementation of the travel credits scheme , and the traveler is bound by his/her own income, so an individual utility maximization model is established considering the travel credits scheme. The study finds that the choice of travel mode under travel credits scheme will change, driving the traveler to choose public transportation. At the same time as the credits prices will increase the cost of private car travel, different types of travelers have different effects under travel credits scheme, analyzing the price effect of travel credits.The research work of this thesis will provide the theoretical basis for the future implementation of the travel credits scheme.