text: Having to worry about driving a car may produce more stress in a persons life.  In Source three, it says, "It's a good opportunity to take away stress and lower air pollution."  This tells us that riding in an automobile, while the roads are very crowded, causes people to worry about whether or not they are going to be in an accident.  Also, it has been proven that exercise helps to lower stress, and by riding a bike instead of driving a car, stress may be lowered by simply using your resources to get where you need to go.  In Source one, it tells us, "When I had a car I was always tense. I'm much happier now. (Heidrun Walter, mother of two)."  This proves that people are worried about their car and if it might break down, or something worse.  Something can always go wrong with a car, whether it be trouble with the engine or you accidently locked your keys inside, and it becomes very expensive when you have to fix a small blunder.  By limiting car ownership, less people have to worry about their automobile.