true, perhaps one day the worlds economy will be so bad that will be the only way people can afford to get around is through public transportation.
however like i said, you elimiate the private automobile, you eliminate a lot of jobs, as a lot of jobs are focused on fixing, making, or making parts components and peaces for the automobile.
in addition to what your saying, some people drive when they could just WALK!!!! for example my dad driving not even a mile to get to the gas station or beer store when he could be walking a simple 15 minute walk and getting some excersize, some distances you don't need to drive, and thats the issue with this generation, a lot of the solutions could be solved buy, walking... or riding a bike...