Asked on Reddit 
One response…
I seen a dude selling air on the beach in pismo California.
People driving on the beach air down their tires for traction. The closest place to air them back up was like a mile from the beach entrance.
This guy got a trailer with a huge compressor a few hose reels and he’s charging $1 a tire to air u up. He had a line of trucks and trailers all day…
He’s been there for years so I’d guess he’s doing well. He’s never waiting he’s always busy I’m sure he’s aware of peek times to be there. And at $1 a tire one truck and trailer is $8 to $10 per vehicle.
This could work at any popular drive-on beach spot, start with a small compressor and scale up if there’s demand 