Road Pricing For A Bi-modal Transportation Network With Emission Considerations

The adverse effects of traffic emission have attracted people’s significant attentions in the increasingly serious air pollution situation of China. And we have sufficient reasons to believe the effects will bring us greater challenges in the future with the continuous development of urbanization process. Based on this background, this paper attempts to explore a way of making the pollution of traffic emission reduced in some extent. After the studying about the existing related research, we find that road pricing may be the good way to get it. Based on this idea and traffic assignment model with others, this research begins.First of all, the second chapter introduces some relevant contents about traffic assignment model with focusing on the dual-mode variational inequalities model considering asymmetric interaction between two modes. And then this paper considers emission constraints and objectives into the model given in chapter two. For different management objectives, such as minimum system emissions, minimum system time cost or total cost, minimum total charges and so on, some corresponding bi-level programming models are given and discussed. A numerical example for these models with Genetic Simulated Annealing Algorithm Constitutes the main contents of chapter four. According to the numerical example, some conclusions are got.Policy makers can achieve their goals, such as reducing the system emissions, the total travel time, total travel cost or others, by charging to car travelers. If the road pricing policies are implemented, the bus travelers’cost will reduce immediately because of the decreasing of road crowding. At the same time, the car travelers’total cost may not increase significantly or even decrease. For the bus travelers transforming from car travelers because of the charging, their travel time may decrease even though the speed of bus is slower than bus’s. So an interesting conclusion comes out. Charging may be beneficial to everyone. Although the charges could solve some problems, but it doesn’t mean that the more charge, the better result. In addition, the vary charges in each link is better than the same. There may be a contradiction between the target of minimum system total emissions and the target of minimum system total cost or minimum system total time. When they contradict with each other, the paper also gives a lot of discussion about it. Besides, the sensitivity analysis of the parameters show that improving the car’s average number of passengers can be very effective in reducing systems emissions, and so is reducing the traveler’s preferences for cars or increasing the attractiveness of buses.Based on the research of this paper,a satisfactory answer about how to make system total emission reduced or controlled has been given by the way of emission charge. Not only that, the detailed analysis of the impact of emission charges to the system has also been given in the research.