[davepl]

Even as recently as the 90s I was driving my '69 Pontiac 427 though the northern lakes route of the Trans Canada (the I-90 but north of the Great Lakes more or less) and there were stretches of several hundred miles without fuel at night. My car barely made it, and one of these trucks with a camper would have no shot.

So, they added extra tanks. But there are more fuel stations now.