sleeping policeman
减速垄，减速带
释义：
a narrow raised part in a road which makes traffic go slowly 减速垄，减速带(为防止车速过快而横设于路面的隆起物)，是 speed hump 的非正式形式。
例句：
We should slow down when we pass the sleeping policeman.
The 'sleeping policeman', with white markings, was put in halfway down the 100- yard cul-desac to 'calm traffic'.
