针对快递企业的配送车辆在城市配送过程中空载严重的问题，在多家快递企业实施共同配送的前提下，考虑车辆同时取送货对车辆装载率的影响，以配送系统总成本最小化为优化目标，建立考虑同时取送货的城市共同配送路径优化模型，并设计改进遗传算法进行求解，最后通过算例分析验证了模型和算法的实用性与有效性。

In order to minimize the total cost of distribution system and increase the vehicles' loading rate, the influence of simultaneous pickup-delivery on vehicles' loading rate is considered and a VRPSPD (vehicle routing problem with simultaneous pickup-delivery) model for urban express common distribution is established under the condition that express companies carry out joint distribution. Then an improved genetic algorithm is proposed to solve the model. Finally, the practicability and validity of the model and algorithm are tested by examples.

国家科技支撑计划资助项目（2015BAF05B03；2015BAH46F01）；国家科技重大专项04专项课题（2016ZX04004-005）；重庆市重点产业共性关键技术创新专项项目（cstc2015zdcy-ztzx60009）。