You also have to remember that in addition to smaller and much more efficient cars (in general), the rail infrastructure in Europe is 100 times better than anything we have here in the states.
Things like a 45 minute commute in Italy or Switzerland can be tackled with a high speed commuter train - and mind you, those trains are awesome! Clean, efficient, etc... Not like the mess that we have here, where the rails don't go anywhere useful, and the trains are in terrible shape (that is, if you're lucky enough to have one at all. We have Metra here in Chicago. It's only good if you need to get INTO the city, not OUT of it.)
They also have bullet trains to get between countries or farther distances when needed. For example, earlier last year, we took a bullet train from Brussels to Paris. The trip was 1.5 hours. Can you imagine doing that, rather than having to fly? It's exponentially cheaper to do that over there.
We've been to 9 different countries in the last 4 years, and have yet to come across one of them that does not have a better commuter rail system than what we have here - either inner city or farther out.