I was intrigued by your reply to PC, Portishead over the problem of a speed hump installed by their neighbours on a Private Road. I would suggest they certainly need to consult both their property deeds and also a solicitor specialising in land and property to get a proper legal opinion.

An ordinary local solicitor may not be best placed to give the correct advice. It is almost certain that either the road is jointly and severally owned by each individual property owner within the cul-de-sac and/or each has a Right of Way for free and unencumbered access along his 'Via trita'. No one individual or group of individuals can jointly act to deprive another of or impede their Right of Way i.e. this is not a majority vote, every affected individual would need to agree and so, on the face of it the neighbours have acted illegally in placing a barrier across the road.

There are legal precedents going back at least as far as 1668 on matters such as the ploughing of a right of way or the placing of logs across it and the like. If, after having first requested their neighbours to remove (or reduce) the offending barrier to their free and unencumbered Right of Way, the neighbour(s) still refuse then the affected party would likely be within their legal rights to remove it themselves whilst being careful to place all the materials so removed onto the property of the offender(s) so as not to be accused of theft.

Again proper legal advice should be obtained before taking any action but the threat of being prosecuted for criminal damage is probably a red herring.