Are there any restrictions at the location?
They shouldn't do that obviously.
That is just plain obstruction of the highway.
however, the reality is that the police tend to be slow to prosecute pedestrians and other members of the public for this offence largely because they are too busy mediating relationships squabbles that we euphemistically call 'domestic abuse'.
But they can't obstruct a public highway in this way if you are asking me about academic law.
Can I clarify anything for you?
Well, yes they could get restrictions placed there but they haven't done it.
They would have to meet the critieria. It is not just for the asking.
Yes, there would have to be. Otherwise the restriction would not be enforceable.
I suppose in legal theory it is possible that they have a restriction which isn't signed so they couldn't enforce tickets against anybody else but couldn't themselves be prosecuted for obstructing but that is not really realistic.