9月22日你所在的城市和另外107个城市开展了“无车日”活动，倡议人们选用公共汽车、自行车或步行等绿色交通方式来代替开私家车。该活动得到了全国人民的支持，提高了人们节约能源与保护环境的意识，活动很成功。
下面请你用英语写一篇短文介绍该活动，并谈谈开展该活动的必要性，号召更多的城市和居民参与到该活动中来。
注意：1. 不要逐句翻译，可适当发挥，以使行文连贯；
2. 词数：100左右。
3. 参考词汇： 无车日Car-free Day；开展launch
One poible verion:
Car-free Day wa launched in our city and 107 other citie on September 22, to encourage people to take public tranport, ride bicycle or walk intead of driving private car.
The campaign ha gained much upport all over the country and ha raied awarene among all people of energy aving and environmental protection. It’ a real ucce.
With the development of the economy, more and more familie have bought private car, thu leading to much heavier traffic problem and more eriou air pollution. Therefore, I think it’ neceary to launch uch campaign. And I hope more and more citie and their reident will take part in thi type of activity.