私车合乘对城市私家车增量的影响研究

Impact of Ridesharing on the Variance of Car Increments

随着滴滴顺风车等私车合乘匹配平台出现,私车合乘在我国开始流行。不同于以私家车出行为主的美国,在以公交出行为主的中国,私车合乘在诱使一部分打算购车的用户放弃购车的同时,也可能使得一部分原本无法承担拥车成本的用户购车并提供合乘服务。本文基于差异化选择理论和均衡理论研究了用户购车决策和出行模式选择行为,并通过算例指出私车合乘可能促进也可能抑制城市私家车增长,取决于私车合乘的费用分摊机制。

With the fast development of real-time matching platforms such as Didi, ridesharing becomes popular around the world in recent years. Different from the USA where most people drive alone to travel, this paper points out that its impacts on car increments is two-sided in China where public transit is popular. On one hand, ridesharing provides an attractive travel mode, therefore may persuade some travelers to give up their vehicle purchase plan; on the other hand, the cost of private car driving is shared, so that some travelers who originally cannot afford a car may be induced to purchase cars. In this paper, we model the car-purchasing and travel mode choices of travelers whose value of time is heterogeneously distributed and increases with time. Based on the model, we demonstrate the impact of ridesharing on the variance of car increments through numerical examples. As shown in our numerical example, ridesharing may accelerate or decelerate the increase of car ownership, depending on the design of driver-rider cost sharing strategies.