speed bump

Speed bump and warning signs A road sign "Humps for 1 mile" in Hertfordshire, England Speed bumps are a class of traffic calming devices that use vertical deflection to slow motor-vehicle traffic in order to improve safety conditions. Speed bumps are also known as a sleeping policeman in British English, Maltese English and Caribbean English, a judder bar in New Zealand English, and a lying-down policeman in Colombia, Dominican Republic, Hungary, Croatia, Serbia, Estonia, Lithuania, Slovenia, Bulgaria and Russia. Variations include the speed hump, speed cushion, and speed table.

The use of vertical deflection devices is widespread around the world, and they are most commonly used to enforce a speed limit under 40 km/h (25 mph).