The reason for lockers is so that one can park one's bike and all one's belongings, then head down to the beach like everyone else likes to do without concern of theft.
Somehow I think campgrounds are slightly more secure than waysides.
It would be an interesting thought to do waysides without pullouts. Just a sign and a trail down to a clearing, and then down to the beach or point of interest.
What would support vehicles need? Vacuum trucks? Perhaps enough room for a single vehicle to pull out (with a no parking sign).
Pack it in, Pack it OUT policy?