The gas station owner is not making enough money to stay in business. He sees all the transients who have been uprooted and who come to his station for gas and he realizes that he will soon be one of them. This, naturally, is a worry and a concern.
Also, the nicer cars and the more wealthy patrons do not buy gas at his store. They go to the newer, larger gas stations. Those stations are simply newer and nicer and shinier. They are a class above him. This means that the independent businessman is going to be edged out.
In this way, again, the gas station owner is aligned with the transients in poverty, in power, and in despair.