If people limited the use of cars the earth would be able to have enough time to clean its atmosphere, but the only downside to this is that in cities buildings are farther away then they are like in passage 1 where as everything is in walking distance, but in cities that are meant for walking to different locations would cause a major problem with older adults. I do see this happening in small towns but cities would be more difficult to travel to unless they rebuilt everything within walking distance.

Now if America's citizens are driving less each year then let it happen and in a few years come back to the data that is presented in passage 4. So basically let it all happen on its own and not have to force it like Paris has done with giving out fines for whoever is driving a car with odd numbered license plates on mondays and even on tuesdays. I hig    