Do car restriction policies effectively promote the development of public transport?

Traffic problems caused by the rapid growth of motor vehicle ownership have become an increasingly serious concern. Many cities have developed car restriction policies to relieve traffic pressure. Car restriction policies mainly refer to traffic policies used to restrict car usage and to control the growth of vehicle ownership. These policies include driving restriction policies for restricting car driving and the license plate restriction policies for limiting vehicle purchases. In this paper, the policy effectiveness evaluation method based on panel data was used to analyze the effect of car restriction policies on public transport development. The influence of a driving restriction policy, a license plate restriction policy, and a dual policy implementing the two on the development of public transport was analyzed for six cities in China. We found that the driving restriction policy increased public transport passenger volume by 5–25%, the license plate restriction policy had no significant effect, and the dual policy increased the volume of public transport by 20–30%. Notably, the integrated policy enlarged the policy effect. However, because the car restriction policy had no significant impact on the proportion of public transport, these types of restriction policies cannot radically improve the traffic mode split. That is, car restriction policies can merely serve as a kind of emergency measure, rather than solving the traffic problems at the source. Only by improving the planning of urban roads, increasing the public transport infrastructure and increasing residents’ acceptance of public transport can the traffic mode split be fundamentally improved.