June represents the beginning of Summer, Grads and Dads, and since school is over, for many families that means summer vacations. That in turn means (like them or not), there's no avoiding RV's on the road.
Motorcycles are RV's too! I did this goofy drawing of a over the top dresser in about 1973.
By the way, for many years I've thought "Vacation" was a weird way of putting it. I think the English have the right idea when they say, "I'm going on Holiday".