城市道路中排放收费对合乘的影响

为研究城市道路中排放收费对合乘的影响，建立了双层规划模型.下层规划描 述了出行者的出行方式选择及路径选择；上层规划以社会福利最大化为目标.设计了启发 式求解算法并通过一个算例得到了路段最优收费费率、交通需求、社会福利、出行费用和 排放量.算例结果表明，排放收费可提高社会福利，促进更多的出行者选择合乘，而合乘不 会抑制交通需求；合乘成本对合乘的影响有限；排放权重系数越大，社会福利越高，系统 效率也会提高；燃油效率越高对系统不一定越有利，应根据实际的路网结构进行建模分 析，制定最优费率.

Impact of Emission Charging to Carpooling in Urban Roads

In order to investigate the impacts of emission charging to carpooling in urban roads, a bi-level programming model is proposed. The lower level describes the travelers’selections of travel modes as well as route choices while the upper level aims to maximize social welfare. A heuristic algorithm for the computation of the optimizing value of link toll patterns, traffic demands, social welfare, travel costs and emission is designed and then applied to compute solutions to a numerical example. The results demonstrate that emission charging could increase social welfare and facilitate more people to carpool, and carpooling do not restrain traffic demands. Carpooling cost has limited impact on carpooling and the social welfare promotes with higher emission weight coefficient as well as system efficiency. It is not always beneficial for traffic system with higher fuel efficiency. Thus it is necessary to capture optimal toll on the basis of the topological structure of traffic network.