One year, riding across the US to one of the rallies, we were crossing a midwest state that at each exit, had a sign telling you how far the next exit with fuel was. That was great. Once I had run out of fuel with just the left side tap on, if it was just a couple of miles to one exit, but the next exit with fuel was only a couple more, I would skip the first exit and keep going, and so on. Plus, I would pop the cap off and look to see if I could see fuel at the bottom of the tank. Once, I looked in, and I could see dry floor on the inside of the tank, but there was still some fuel towards the back, being lower. I made it to the next stop, but that was cutting it a little too close.
There is a particular highway in Nevada that has a stretch of over 100 miles with no fuel available. I always had to make sure I filled up the tank as full as I could before that stretch, and at the other end, the bottom of the tank was like that, dry up towards the front. There was a nice downhill stretch leading up to that exit (going north at least), just in case.