I researched this subject when we had a neighbour's taxi parked more ore less permanently on a junction causing sightline problems etc. The statute and regulations which give the police powers to require a vehicle causing an obstruction on the highway to be removed. I hope these references will be of use to the Police should they reinvestigate this matter.
"Wilkinson's" refers to Wilkinson's Road Traffic Offences which is the standard textbook.
• Regulation 103 Road Vehicles (Construction and Use) Regulations 1986 and (causing or permitting a vehicle to stand on a road so as to cause an unnecessary obstruction) [Wilkinson's 6.204];
This states that no person in charge of a motor vehicle or trailer shall cause or permit the vehicle to stand on a road so as to cause any unnecessary obstruction of the road. Only the Police can enforce this and make the decision as to whether a vehicle is causing an unnecessary obstruction. The outcome of each investigation will depend upon many factors, such as the size of the vehicle, the type of road, its position in the road and the use of the road.
• Section 137 Highways Act 1980 (wilful obstruction of the highway) [Wilkinson's 6.204]:
— (1) If a person, without lawful authority or excuse, in any way wilfully obstructs the free passage along a highway he is guilty of an offence and liable to a fine not exceeding level 3 on the standard scale.
To quote the Crown Prosecution Service "the prosecution of traffic offences is vital to the enforcement and promotion of road safety and the protection of the public."
Unfortunately, both of these powers are discretionary, so the Police are under no duty to act. You would have to get a writ of mandamus from a Court to order the Chief Constable to act. Expensive and risky.
Our problem was solved when the owner of the taxi was cautioned for assaulting a neighbour (advised how to report the attack to get the police interested) and thus lost his licence.
Have you tried interesting your local newspaper? Some photos, and copy - include interviews with locals who have had near accidents etc, should get them interested. Ambitious coppers don't like bad PR. Good luck.