sleeping policeman (UK)
noun phrase

- a small raised area built across a road which forces drivers to slow down.

(Cambridge Advanced Learner’s Dictionary)

—
HISTORY

A sleeping policeman is a colloquial term for a speed bump/speed hump. As the phrase implies, it acts as a type of policeman to slow traffic or reduce the amount of traffic flowing through a particular street.

Exactly when the first sleeping policemen were invented is unclear. But in 1906, the New York Times reported that Chatham, New Jersey planned to install what were probably the first automobile speed bumps/humps ever by raising its crosswalks five inches above the road level.


The sleeping policeman has its critics who claim it increases noise pollution, causes vehicle damage and delays the arrival of emergency vehicles, which in turn can cost lives.

—
THANK-YOU-MA’AM

A sleeping policeman should not be confused with “Thank-you-ma’am”, American slang for a normal bump or hole (pothole) in the road. The Oxford English Dictionary says this term was inspired by the fact that hitting one of these obstructions “causes persons passing over it in a vehicle to nod the head involuntarily, as if in acknowledgement of a (female) favour.”

—
SYNONYMS

speed bump, speed hump, road hump, speed breakers, speed ramp, speed cushion, speed table; traffic calming device; judder bar (New Zealand), lying-down policeman (Croatia)

—
Practice OWAD in a conversation, say something like:

“I wish someone would invent a linguistic SLEEPING POLICEMAN to slow down fast speakers.”

—
A BIG THANKS to my “Friends-of-OWAD” who are supporting my efforts to keep the service going :-)

https://donorbox.org/keep-owad-alive