What are speed bumps and how do they work in the UK?

Speed bumps, also known as sleeping policemen, are traffic calming measures designed to reduce vehicle speeds in residential areas, near schools, or other high-risk zones. They are raised sections of tarmac, typically 50-100mm high, forcing drivers to slow down to avoid discomfort or potential damage to their vehicle. In the UK, they are regulated by local authorities and must comply with specific dimensions outlined in the Traffic Calming Regulations.

Speed bumps work by creating a physical obstacle that disrupts smooth driving. When a vehicle approaches at high speed, the abrupt elevation change causes a jolt, encouraging drivers to reduce speed. There are different types, including flat-topped humps, round-topped humps, and speed cushions (wider bumps that allow emergency vehicles to pass unimpeded).

The effectiveness of speed bumps depends on their design and placement. Studies show they can reduce average speeds by 10-15 mph in 85th percentile traffic. However, they may increase noise and emissions due to frequent acceleration and braking. Some modern alternatives, like chicanes or road narrowing, are also used to achieve similar results with fewer drawbacks.

For drivers, the key is to approach speed bumps at a controlled speed (usually 15-20 mph) to minimise impact. Lowering speed reduces wear on suspension components and improves passenger comfort. Electric vehicles like the Nissan Leaf, with their instant torque, can navigate them smoothly if driven carefully.

Speed bumps (called 'sleeping policemen' in the UK) are traffic calming devices installed on roads to force vehicles to reduce speed, typically made of rubber or metal with yellow/black markings for visibility. In the UK, common speed bump types include traditional humps (75-100mm high) used on 20mph zones and speed cushions that allow emergency vehicles to pass. Popular UK car models like the Mini Electric and Vauxhall Corsa-e must slow to 15-20mph to comfortably pass speed bumps without damaging suspension. Transport for London data shows properly installed speed bumps can reduce accidents by up to 60% in urban areas. The Highway Code (Rule 153) advises drivers to reduce speed when approaching road humps to minimise discomfort and vehicle wear. Modern designs like sinusoidal speed bumps in cities like Manchester cause less abrupt impacts than traditional square-edged versions while still achieving 20-30% speed reduction.