Autogrumble by 'GOM'

5. Getting the Hump

Road humps as so-called “traffic calming” are the wrong solution for any number of reasons including:

• They cause damage to vehicles with low fronts or limited ground clearance;
• They waste energy by forcing vehicles to slow down and speed up repeatedly, using lower gears;
• They cause more noise and pollution for the same reason;
• They distract drivers from looking out for other road users;
• They cause discomfort and possibly injury to ambulance patients, particularly those with spinal injuries;
• They discriminate against smaller vehicles. We should be encouraging people to use smaller and more economical cars, not forcing them to buy big 4×4s and SUVs. A large SUV is much more dangerous to pedestrians than a low, smooth-fronted sportscar yet it can take the humps at much greater speed;
• The smaller “cushions” are particularly bad for small cars. If you put one wheel each side you are likely to hit the exhaust system on the hump. The alternative is to drive in the middle of the road, between the cushions. Large vehicles can straddle the humps with impunity;
• Far from calming traffic, humps make drivers more angry and they are likely to drive faster between the humps.

If councils wish to slow traffic down they should set sensible speed limits and enforce them with cameras and spot checks. The effort and materials used for building humps should be used to repair potholes instead.

Another device used to frustrate drivers, the slalom (which forces vehicles to negotiate zig-zag course with priority to one direction) also wastes energy and causes more emissions by causing traffic to wait for a gap. Even worse, drivers may be tempted to make a dash to get through before an oncoming vehicle that has priority.