This, of course, is probably stating the obvious to most Americans on this board, but what I want to say is that cities built around the car are not an inevitable law of nature, but a conscious design choice in city planning. Most American cities saw much of their expansion during a time when gasoline was cheap and plentiful, and to the people of the time, going everywhere by car was a sign of their newfound wealth - and they couldn't even conceive of even wanting to travel by any other way.
But now that the days of cheap oil are apparently over - and it is unknown whether they will ever be back - this is going to be a huge problem.
Commuting to work, or even just shopping for groceries by car, will become increasingly expensive, thus putting even further strain on the already shaken American economy - and this problem won't go away easily even once the economy recovers, since oil prices likely will still be high. Clearly, something needs to be done here.
To my mind, there are two main options. One is improving public transportation. There seems to be a strong stigma among many Americans - especially among those who have never lived in a city with a good transportation system before - against public transportation as a "poor man's transport" and as being slow and inefficient. And after my experiences with the local bus system in Columbus, I can understand that. But again, that's not something inevitable but merely the result of a lack of political will. A larger number of European cities - and quite a few cities in North America as well - have a widespread and efficient public transportation system with frequent stops along major routes throughout most of the day, to such an extent that even people who could easily afford to commute by car will take the bus because it is more convenient - and cheaper. Yes, such a system will likely require some subsidies to set up. But when compared to the subsidies that are used to expand the streets and freeways, would it really be that more expensive? And let's not forget the added benefits of reduced traffic and cleaner air...
The other possibility - which would involve a lot more effort than the first one - is to redesign the overall physical infrastructure of the cities. From what I've seen, American cities are often extremely wasteful when building new neighborhoods. Yes, all those enormous lawns look pretty, but do people really need them? What do they actually do with them, especially when they have no kids who could play around in them? In the end, they just contribute to the sprawling nature of the city and increase the distance to anywhere where you might need to go. Shops where you can buy groceries often tend to be clustered together at locations far from many homes, instead of being spread out through residential areas, again increasing the distance between your home and your destination. Conversely, there seem to be few, if any bicycle lanes that would make it easy to travel medium distances - and it's often just about impossible to simply walk to a nearby neighborhood without walking alongside a street that doesn't have any sidewalks.
Cities like Copenhagen - which has a population density lower than that of many American cities - have succeeded in restructuring the way they operate so that one-third of all people commute to work via public transportation, and another third commute by bicycle. I am sure that with enough effort and political will, many American cities could achieve similar results - and this option is increasingly looking better than the alternative. Mind you, I'm not arguing for abolishing the car - it still has its uses from time to time, and I am sure that most of those Copenhagen commuters still own one. It's just that I think it is important to offer genuine alternatives, so that the inhabitants of a city have the freedom to choose what mode of transportation they will use.
Some links of relevance to this topic:
Copenhagenize - Life In The World's Cycling Capital
Common Urban Myths About Transport
What are your own thoughts on this?