Verizon travel app and I-exit both list gas stops. If I am not entering an obviously RV friendly fueling station I try to drive slowly by the gas stop and clearly view my exit route before entering. This may require that I drive around the block or down the street and around. Still, I have found, from bad experience, that what looks like a clear exit may be blocked in back by all kinds of debris. I also look for stations with diagonal fueling stations or stations parallel to the street. Since I seldom travel more than 2 hours without some type of a rest, I will start looking for fuel stops at 1/2 full, and I will look seriously at 1/4 full.