If the OP was meaning literally getting gas (as opposed to diesel) then the truck stops sometimes are not very friendly to a long gas TV pulling a long TT since the truck islands are often diesel only. So you still have to use the gas islands with the cars. Flying J sometimes has dedicated RV lanes that have all fuel pumps and even dump stations.
Looking at a satellite view on a map program can give you an idea of the layout of fuel stops ahead of time if you can figure out where you might be when you need to fill up.
We tow a 32ft TT with a long bed gas pick-up and we have had a few "adventures" getting gas. But then, RVing is supposed to be an adventure.
One other point: ease of access trumps price of the fuel. So if the well positioned station is more convenient than the cheaper place, I'd spend a few cents more per gallon and enjoy the stress-free stop.