地铁建设与交通限行对于城市空气质量影响效应的比较——地方政府实施“疏”“堵”政策之争

Comparison of the Effects of Metro Construction and Traffic Restriction on Urban Air Quality——Should be “Dredging” or “Blocking” by Local Government

我国诸多城市面临严重的环境压力问题,决策者进行了多种手段的尝试,譬如通过发展地铁缓解交通压力,或是出台限制私家车出行的政策,这两种手段可以视作为一项"准自然实验"。通过对两类政策的实施效果进行比较分析,并对两类政策的协同性进行检验,结果发现解决交通环境问题的疏通类政策(地铁)更为有利,但作用效果会逐步减弱,限行政策对空气质量的影响有限,但对一些城市而言,两类手段共同实施的效果会更为突出,决策者应控制好两类手段实施的力度与协同性作用。

Many cities in China are faced with serious environmental pressure. Policy makers have tried many means, such as developing metro to ease traffic pressure or introducing policies to restrict private car travel. These two methods can be regarded as a quasi-natural experiment.The study points out that the dredging policy (metro) to solve the traffic and environmental problems is more favorable, but the effect will gradually weaken, and the restriction policy will have a limited impact on air quality. However, for some cities, the effect of the two methods will be more prominent.It is pointed out that policy makers should control the intensity and contingency effect of the two methods.