most traffic congested city (Fukuda). During rush hour,the average speed of vehicles in downtown Bangkok is less than 10 km/hour (Vogt).These vehicles cause traffic pollution, a direct emission which is physically harmfulto humans. Car exhaust emits one-third of the nitrogen dioxide that can contributeto acid rain which is harmful to both humans and the environment (Bruning 55). Airpollution caused by traffic jam is one of the very important problem that need to besolved immediately. The followings are some steps