A hump in the road intended to cause traffic to reduce speed.
〈英〉“隐身警察”（指为防止车速过快而在道路上建造的路面突起）；减速路坎
Example sentencesExamples
Rumble strips, sleeping policemen and flashing signs have the same benefits.
Still, demands persisted for speed cameras, radar traps, sleeping policemen, chicanes and other traffic management.
Chairman Derek Whitnell said: ‘We have asked several times for something like a sleeping policeman to stop the rat-run that goes down here, but nothing gets done.’
We need some traffic calming measures like sleeping policemen to slow cars down.
Round our way, we've had a lot of success in the area of speed reduction with sleeping policemen.
Hardly anyone objects to the lower speed limit but people do have genuine concerns about noise and vibration caused by things like sleeping policemen.
And are we expected to believe that when these sleeping policemen are being placed on the road the very same people will not complain at the disruption caused?
I am all for sensible traffic-calming, rumble strips, sleeping policemen and so on to keep traffic flowing, but these chicanes are a nightmare and should be dug up and replaced.
Our roads don't need sleeping policemen - they have created a much cheaper way to slow the traffic down (plenty of holes in the road do the same thing).
Bexley Council in their wisdom have now decided even the main roads need sleeping policemen.