Speed Bump

A speed bump is a traffic calming device that uses a vertical rise in the road surface to slow motor vehicles, known in other places as a sleeping policeman in British English, a judder bar in New Zealand, or a lying down policeman across eastern Europe and Russia. Chatham, New Jersey, tried an early version in 1906, planning to raise its crosswalks five inches above the road as an experiment against speeding, but the modern design is credited to the physicist Arthur Compton, winner of the 1927 Nobel Prize in Physics, who built traffic control bumps in 1953 after watching cars speed past Brookings Hall at Washington University in St. Louis; the first European speed bump followed in Delft in the Netherlands in 1970. A typical bump stands 8 to 10 centimeters high across a traverse distance of under 0.3 meters, forcing drivers to slow to about 10 to 15 kilometers an hour, and the design works best on streets with a posted limit under 40 kilometers an hour. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/