Close to me in Cambridge, there is a thing called a guided busway. It's a road exclusively for buses that has guide rails so the bus doesn't have to be steered – it means that the road can be narrow enough to go on an old railway bed. Beside the busway is a shared path for bikes and pedestrians - it's an incredibly good, safe route into town.
This excellent path recently acquired a speed limit for bikes of 15mph, complete with radar speed signs. Meanwhile, close to another place I've lived in Wandsworth in London, the police are using radar guns to fine cyclists exceeding a 12mph limit in some of the borough's parks. I know of other examples. I'm beginning to suspect it might be becoming a thing.
