Continuum Model Of Traffic Equilibrium And Its Application In Traffic Planning

Traffic assignment model and its algorithm are a fundamental theory of transport planning. In modeling traffic equilibrium problems for a transportation system, two different approaches, the discrete and the continuum modeling approach, are commonly adopted. The continuum modeling approach is mainly used for initial planning and macroscopic studies. This thesis aims to develop the continuum modeling approach for transport planning in order to avoid traffic congestion. The thesis focuses on the applications in road alignment, CBD location and rail transport. The main works are as follows:1 Cars following states are studied, it is shown that velocity of following car depends on the following distance of the preceding car and velocity of preceding car. When the preceding car is slower than the following car, the effect is more obvious. Based on the characters, a new generalized force model which is based on the maximal velocity is proposed. The model is used to simulate the state which the cars pass the signalized intersection and the cars following state. The simulation results show that the new model can eliminate the large distance between cars on the red light and has better features than former model.2 Traffic equilibrium and topology optimization are imported to route planning problem. A user-optimal model and algorithm for initial route planning are proposed based on transport planning and structural optimization theory. Continuum traffic equilibrium model is used to describe the commuters' behavior flexibly. Evolutionary structural optimization (ESO) is used to delete the low flow intensity parts step by step, update the flow intensity of remainder and get the parts in which flow intensity level is uniform and concentrated finally. Then the initial location of future artery is found. A numerical example and an appraisement method based on traffic performance are given to demonstrate the effectiveness of the proposed methodology.3 In realistic traffic network, travelers can either travel directly to the CBD on the continuum (surface streets), or they can travel on the continuum and then exchange at an interchange (ramp) before moving to the CBD in the fast road network. According to this character, the total cost from a demand point to CBD includes travel cost of surface streets and travel cost of fast road network. A continuous model is proposed further. A numerical example is given to simulate changes in the traffic flow intensity and the users' number on CBD after adding a CBD in the city. The model is used to analyse the case of Xi'an quantificationally. When a new CBD is built in Jingkai Area, how the traffic flow in Bell Tower Area will change. 4 Road traffic time is affected by vehicle's velocity, boarding and debarking people number, and road congestion. On the contrary, rail transport mode is clocklike and rapid. So users who choose different traffic mode will perceive different traffic time. According to this character, a perceived bias is added into the travel cost of fast road network and a traffic equilibrium assignment model based on perceived bias is proposed. The model is used to study how the traffic mode affects the traffic flow distribution. The case of West Rail Line in Hong Kong is analysed the model.