随着经济的发展,我国汽车保有量不断增加,尤其是近两年来城市汽车保有量逐年攀升,汽车排放污染物已经成为城市大气污染的主要来源。有资料表明,国内一些大城市的汽车排放污染物,对多项大气污染的指标贡献率已经超过60%,直接危害城市居民的身体健康。根据统计,城市行驶的汽车有8 With the development of economy, the car ownership in our country keeps increasing. Especially in the recent two years, the car ownership in cities has been increasing year by year. The pollutants emitted by cars have become the main source of urban air pollution. Statistics show that the emissions of pollutants emitted by vehicles in some major cities in China have contributed over 60% to the targets of many air pollution projects and directly endanger the health of urban residents. According to statistics, there are 8 cars in the city