Abstract: Research showed that the factors influencing public transportation share ratio included two :first was the influence of decision-makers（the government planners and city-land utilization）; the second was the influence of users mainly reflected in the travel cost, travel time and the comfort.The above mentioned main factors were selected affecting public transportation share ratio, namely public interests and individual interests based on multi-objective function, and then constructed multi-target calculation model was set up to calculate public transportation share ratio and solving steps of this model were provided. For public interest factors, road occupancy area was selected to construct calculation model; for the individual , generalized-cost and in-car-congestion-level calculation model was built. Finally, relevant data of Nanjing were used to calibrate the model, and then this model was applied to Nanjing. The calculating results showed the irrational area occupied by public traffic, reasonable cost and unsuitable congestion level during rush hours. These calculation results coincided with the reality of public traffic in Nanjing, thus proving that the model could be applied to calculate the public transportation share ratio in big cities.

Key words: traffic and transportation engineering；urban traffic, public transportation share ratio, calculation model, multi-objective function optimization model, influence factors

摘要： 公交分担率的影响因素包括两方面，一是决策者的影响（政府规划者和城市土地利用）；二是使用者的影响，主要体现在：出行费用、出行时间和舒适度。基于多目标函数原理，选取以上影响公交分担率的主要因素，即公共利益和个人利益，构建多目标公交分担率测算模型，并给出模型求解步骤；对于公共利益因素选取道路占有面积并构建测算模型，对于个人利益则构建广义费用及车内拥挤度测算模型；结合南京市相关数据，对模型进行标定应用。计算表明：南京市公共交通道路占有面积不合理，费用合理，高峰小时拥挤度不合适，测算分析结果与南京实际情况相符合，表明该模型可用于大城市公交分担率测算分析。

关键词: 交通运输工程, 城市交通, 公交分担率, 测算模型, 多目标函数优化模型, 影响因素