Cars dominate the American landscape for a variety of reasons: the way our communities are constructed, the various subsidies in place, politics, and, of course, the money that car and oil companies can make by pushing their wares.
Advertising helps keep the car markets going strong. Can you imagine a world where public transportation had a similar budget to create TV ads on par with the automobile variety? Maybe commuters would come to believe that riding the train had just as much sex appeal as sitting in traffic in a Lexus SUV.
For a vision of what such a world might look like, check out this ad for Madrid Metro: