road safety device known as a sleeping policeman crossword clue

 The road safety device known as a sleeping policeman is a speed bump.

Speed bumps are raised sections of road that are designed to slow down traffic. They are often used in residential areas and near schools to make the roads safer for pedestrians and cyclists.

The name "sleeping policeman" is thought to have originated in the United Kingdom in the early 1900s. The bumps were sometimes placed in front of police stations to slow down traffic and make it easier for the police to catch speeders.

Other possible answers for the crossword clue "road safety device known as a sleeping policeman":

SPEED BUMP

TRAFFIC HUMP

SPEED REGULATOR

SLOW ZONE

CHUMP

I hope this helps!