People still need to get from Point A to Point B. Goods still need to get from the factories to the stores. Etc. The real crisis will come at exactly the point that the price of gasoline puts a tourniquet on the physical flow of commerce.
Being all too familiar with D.C. traffic patterns, I can safely say that all the PA, NY, NJ, MA and CT license plates I saw in traffic weren't making necessary trips between points "A" and "B".
That said, I think people should be able to drive whatever they want wherever they want. I just see it as a little bit hypocritical to bitch about the price of gas, then hit the road for an Easter weekend getaway.