Speed bumps, also known as traffic thresholds, speed breakers, or sleeping policemen, are a type of traffic calming device that utilizes vertical deflection to reduce the speed of motor-vehicle traffic and enhance safety conditions. Variations include the speed hump, speed cushion, and speed table.
These vertical deflection devices are widely used globally and are typically employed to enforce low-speed limits of 40 km/h (25 mph) or lower. While effective in reducing vehicle speeds, the use of speed bumps can be controversial due to potential increased traffic noise and risk of vehicle damage if crossed at excessive speeds.
They can also impede emergency vehicles. Additionally, poorly-designed ones that are too tall or have sharp angles may disrupt drivers’ experience and prove challenging for vehicles with low ground clearance even at very slow speeds; this is particularly problematic for many sports cars. Moreover, speed bumps present serious hazards to motorcyclists and bicyclists if not clearly visible; however, in some cases creating a small cut across the bump allows these vehicles to pass without obstruction.