I read something just a few days ago about someone making a landing on a road in the UK (Scotland) due bad weather. Apparently the cops were really helpful and supportive.
So, as long as you have a good reason (for anything, actually), no reason to doubt UK Plod's ability to be professional and helpful!
Getting back to the original question, we've done lots of road landings (lots of fun) but never in the UK (or, indeed, nowhere in Europe south of Sweden).