Evaluating Environmental Impacts of Major Road Network Improvement in Beijing Based on a Combined Traffic Demand and Vehicle Emission Model <Article>

Vehicle emission forecast method is developed in this paper. Firstly, it generalizes achievements in traffic planning and methods for vehicle exhaust emission forecast in this field. Secondly, the relationship between the vehicle average speed and its exhaust emissions is established based on the present methods. Finally, data collected from the urban expressway and the arterials in the road network of Beijing is used to calculate the emission factors and to prove the feasibility of this method. So, environmental impacts of major road network in Beijing can be evaluated. it can be shown that using the method combined traffic demand and vehicle emission model to estimate emission factors, the average emission level of three main emissions at some major traffic corridors can be calculated, and this result can be used as a very important factor to evaluate traffic planning project.