Personal transportation is dominated by the automobile, which work on the network of 13 million road,As well as one of the world's longest highway system 248 []. Car market, the world's second largest 249 []. The United States has the highest rate of car ownership of per capita of the world, with up to 765 cars, to 1000 Americans [250] about 40% of personal vehicles, vans. Off-road truck or 251 light []. The average American adults (count all the people and those who don't drive) takes 55 minutes drive every day, traveling 29 miles (kilometers) 252 47 [].