yep as @fm says 30 vans is no joke. If they live near the site they can always have a barrier and a little explanation letting people know where to find them. But if the idea is to allow vans to arrive during 24h some automated way would be better, to avoid needing to get up from bed at 3pm when some surfer kids arrive.

Note that some of this sites also have a fixed schedule, and only allow people to get inside the place from 10am to 10pm (just an example). After that the place is "closed" and no one else can get inside.

Maybe he'll loose one or two clients, but no one will need to be there 247.