Research On Traffic Assignment Model Considering Environmental Effects

With the rapid economic development, the motorized trips proportion of urban transport is increasing continuously, traffic congestion and environmental pollution problems have become more and more prominent. Motor vehicle exhaust and noise pollution seriously affect the urban residents'health and attract more and more attention. Reasonable urban transport planning and transport policies are very important to relief traffic congestion and reduce traffic pollution. However, the traffic assignment technologies commonly used nowadays take little concern of environment and the assignment result cannot provide useful reference while making polices to reduce traffic environment problems. If we can take environmental object into consideration while doing traffic assignment, then we can provide the basis for in-vehicle route guidance systems or electronic toll collection systems of the Intelligent Transportation Systems and achieve the goal of environment pollution control.Firstly, the importance of traffic environment has been discussed. Sustainable development of the traffic environment is the inevitable requirement for the development of urban transport and the health of the residents; we should take traffic environment into concern while doing analysis of the traffic network. Subsequently, the paper discussed the impacts of environment on the traffic flow from the aspects of environmental justice and regional environmental pollution restrictions respectively.In the traffic assignment model, we can consider the environmental factors as the form of the network impedance. Based on the analysis of the traditional road impedance function, this paper established the vehicle air pollution impedance function, vehicle noise impedance function and integrated environmental impedance function with concern of the traffic environment pollution model. Finally, this paper established the traffic assignment model considering environmental impacts, and applied the model in Jinmen urban transportation planning.