Dave.

We live alongside a main road but with a 30 limit.

Sometimes cars & bikes absolutley rip past our place, totally irresponsible as there are junctions, a school, and a blind summit.

Sometimes the speed cops part their van in a layby outside our place, it amazes me the amount of people that drive past either blowing their horns, or shouting abuse out of the window at the cops.

Personally I have no issue with them parking there as in this case, the speed limit is there for good reason.