It's an interesting situation to see how this pans out in a country as large and spread out as the USA.
When it all happened in the UK due to ludicrous amounts of taxation (before my time and I don't actualy know how or why this happened), people simply stopped driving and relied more heavily on public transport (buses and trains designed primarily to carry people, not goods), something that doesn't exist in many parts of America.
Here, apart from major packed together cities like NY. you don't exactly have a choice.
Now in the UK, just about every supermarket delivers. Everyone buys online and because of very strict drunk driving laws people generaly do NOT drink and drive (something I've noticed is a little more overlooked here in the US) and they get the train when they want to go out so they can get smashed and not have to worry about it.
Everyone still has a car, but it's a tactical use, not a use for absolutely everything as it is here.
As Cody kind of points out, the country is pretty much founded on oil use. It's hugely spread out and americans do love their big engines.
So in short, they've got you by the nuts and the most you can do is sell your trucks and buy the smallest engined car you can and pray someone invents something that runs a lot better and cleaner than a petrol based car. It's not like efficient transport systems can be set up overnight.
Dreadful situation that is making a great deal of people very unhappy.