Enrique Peñalosa, former Mayor of Bogota said that "An advanced city is not one where even the poor use cars, but rather one where even the rich use public transport", and imho he is completely spot on with the issue of transportation. The transportation problem in the US is a city/urban planning problem, and not one solved by building more roads and putting more cars on them.
I suggest you watch his TED presentation http://www.ted.com/talks/enrique_penalosa_why_buses_represen...
Another worth watching is that by Bill Ford, of the Ford Motor Company: https://www.ted.com/talks/bill_ford_a_future_beyond_traffic_...