A speed bump is generally an elevation in a specific area of the roadway to force the driver to adapt his speed, or even reduce it significantly. There are two main types of speed bumps. The first, road speed bumps, is intended for private roads. The second, speed cushions, are speed bumps assigned to built-up areas.
The donkey
This is the oldest but also the most common retarder. It is sometimes better known as the “coated gendarme”. Its height is generally ten centimeters and its length is four meters.
The trapezoidal type retarder
This road retarder has a plateau, i.e. a flat part at its top, parallel to the road. Geometrically, a cross section reveals a trapezoid. Its height is generally ten centimeters while its length ranges from two and a half to four meters.
The speed bump for private roads
These speed humps are made of rubber or cement and are usually provided with characteristic colors, namely yellow and black. Their shape is usually curved and they are mostly found in front of hospitals or shopping malls.
The soundtrack speed bump
These are strips placed on the roadway that are intended to emit a dull noise on contact with the wheels and thus attract the driver’s attention. For example, they can prevent falling asleep.
The Berlin cushion
The speed bump is an ingenious device to reduce the speed of vehicles. It is structurally similar to a speed bump. Its special feature is that it is narrow enough to make way for cyclists on the right. Buses are also not hindered and can cross it without touching the two wheels. It plays a great prophylactic role in zones limited to 30 km/h.