We live on a fairly busy road - buses, schools etc, with houses and parking on one side of the road and a school playing field and no houses but double yellow lines on the opposite side. We have severe parking problems most of the time - especially at school drop off/pick up time but tonight our neighbour has tipped up with large caravan to join the general mayhem ! Are you allowed to park a caravan on the public highway ? ?
Strictly speaking, nobody has a right to park on a road unless it is marked as permitting parking. Many people do park on unmarked roads, but that doesn't mean they are doing so legally. It is just that the police are not too bothered until or unless the parking causes an obstruction. "Causing an obstruction" can be an offence. The Highway Code has something to say about this.