That and the M1 I have a theory there are too many road cones in this country for them to store in warehouses so they put them on the motorways for no other reason.Having driven it recently I'd say it's the M6.
Also the silly and dangerous habit of dumping the last few buckets full of tarmac across the road rather than taking it back to the depot. I think that the police are too sleepy to take action.That and the M1 I have a theory there are too many road cones in this country for them to store in warehouses so they put them on the motorways for no other reason.
It will have been steadily increasing in value over those 50 yearsTook my 1975 mk2 escort to bits in 1991 and only uncovered it last year