Abstract: In order to alleviate traffic congestion and construct green traffic system, this paper researches the system optimization problem and proposes a two-stage model in the traffic system with ridesharing. The travel modes are split, and user equilibrium model and system optimal model for traffic assignment are constructed. An efficient algorithm is implemented to solve the problem. The numerical example illustrates the system optimal effect based on time cost and emission cost. Additionally, the change of traffic volume, total time and total emission of the whole system are shown in terms of different emission coefficients.

Key words: ridesharing, system optimal, total time, total emission, emission coefficient

摘要： 为缓解交通拥堵，构建绿色交通系统，研究了以排放量成本度量的交通系统优化问题，建立了针对包括合乘的交通系统的分阶段模型。对出行者交通选择模式进行了方式划分，建立了以排放量衡量的用户均衡和系统最优交通流分配模型，设计了相应的求解算法，并通过一个算例说明了模型和算法的可行性和有效性。通过对比，说明了按时间成本度量的系统最优分配和按排放量成本度量的系统最优分配所能达到的效果；根据不同的排放相对系数说明了考虑合乘的交通系统中交通量、系统总时间和排放量的变化趋势。

关键词: 合乘, 系统最优, 总时间, 总排放量, 排放相对系数