I am struggling with the OP's question "When Traveling..." I can see when at the RV park or home all the compressor ideas to check and top off your tires before the trip...no discussion there. But "when traveling" if something went wrong that you need to air up a tire aren't you needing a tire shop or a auto service? Confused.
I of coarse have a 12v emergency compressor just in case but not sure what it would be good for. Not like I can repair a tire and air it up to seal it on the road. Helped someone once to air up their spare because they did not include it in leveling it off before the trip.