中文摘要：

探讨放射式轨道路网下的系统出行成本，能够为评价轨道交通服务水平、确定合理的线路数量和运营参数提供理论支持。基于研究区域人口密度服从Clark 分布，建立了系统出行成本模型。模型将乘客在步行时间、车站等待时间和车上等待时间换算为费用作为系统出行成本的一部分，结合运营商的运营和维护成本得到系统人均出行总成本。以成都市为例，通过模型分析确定最优发车频率为13 veh/h、轨道线路数为5条，较符合实际情况，验证了模型的有效性。

英文摘要：

Investigation of system travel cost over a radial rail network may lay a theoretical foundation upon w hich the level of services of the rail transit and operating parameters can be evaluate reasona-bly .On the basis of the population density in study area subjected to the classic Clark distribution ,a model is built to calculate the travel cost of the system encompassing both operator and users costs . The model converts the passenger’s access time ,waiting time at the station and travel time on the train to money as parts of the system cost .T he paper also uses Chengdu City as an example to apply the model ,resulting in a grid frequency of 13 veh/h and 5 rail lines .The result is reasonable and show s that the model is valid .