There's a lot of inequity when it comes to the politics of gasoline, a product that used to be the great equalizer for most economic classes. Used to be, even if you drove a heap, it didn't matter if you gassed up next to a guy with a Mercedes-Benz. You still managed to get almost the same bang for your buck. As someone who's owned several heaps in his life, I know the standard operating procedure - which is, the gas tank in a heap almost never gets filled. If you had the money to fill up every time the tank was low, you wouldn't be driving a heap in the first place.
Some heaps actually operate best on a sliver of a tank.
The point is, transportation-related issues tend to have a harsher impact on the poor than anyone else. Poor people need to get to work, to pick up children from day care, to be mobile in a society where mobility defines your responsibilities to your family, employer, even your own self-image. Driving away from gas stations without paying could be just the beginning. It's way too late to expect folks weaned on a car culture to sit at home because the price of gas is too high. When you gotta go, you gotta go.