In reply to petegunn:
AFAIK
The road is a publicly maintained public highway.
The highways land will probably extend to the adjacent wall.
The public and legal vehicles are entitled to use the highway and park within 15 metres of the hard surface.
Access along the road ( and to gateways off it ) must not be obstructed. Typically 3 metres width should be left for fire engines/appliances etc.
There is a huge demand from walkers and climbers for parking in this area.
The mile long road from Seatoller to Seathwaite has been used for this purpose for over fifty years in my experience, and probably since motor vehicles were invented, without major problems.
The most rammed I have seen it, only about half the distance from Seathwaite has ever been used, so plenty spare capacity ATM.
I normally drive to the turning spot, then take the first available space on the way out.