Speed Bump

A speed bump is a traffic calming feature of road design used to slow traffic, or reduce through traffic, via vertical deflection. They are also known as a sleeping policeman in Jamaica, a kipping cop; in British English a speed hump, road hump (not to be confused with the wider speed hump), speed breaker; in New Zealand English a judder bar; in Hiberno-English a ramp. A speed bump is a bump in a roadway with heights typically ranging between 3 and 4 inches (7.6 and 10 cm). The depth of speed bumps is typically less than or near to 1 foot (30 cm); contrasting with the wider speed humps which are typically 10 to 14 feet (3.0 to 4.3 m) in depth.

Speed bumps can be made of recycled plastic, metal, asphalt or rubber. Speed bumps of various sizes can be placed on a road, from using two four foot or six foot devices on it with a space on either side for drainage, and not designed for avoiding the bump on one side of the car. It may also be connected across the entire road surface.

The use of speed bumps is widespread around the world, and they are most commonly found where vehicle speeds are statutorily mandated to be low, usually 40 km/h (25 mph), or 8 to 16 km/h (5 to 10 mph) in car parks. Although speed bumps are very effective in keeping vehicle speed down, their use is sometimes controversial as they can cause noise and possibly vehicle damage if taken at too great a speed. Poorly designed speed bumps often found in private car parks (too tall, too sharp an angle for the expected speed) can be hard to negotiate in vehicles with low ground clearance, such as sports cars, even at very slow speeds. Speed bumps can also pose serious hazards to motorcyclists and bicyclists if not easily noticed, though in some cases a small cut in the bump allows those vehicles to pass through without impedance. Speed bumps cost between $50–200 though they do have to be replaced after wear.