SPEED HUMPS ARE BAD

Depending upon the vehicle and the hump design, going over a hump at a higher speed may cause less discomfort than a lower speed and accelerating after negotiating a hump generates more pollution than if the hump hadn't been there. The Transport Research Laboratory in the United Kingdom conducted emissions tests on roads with a 75 metre hump spacing and found CO emissions increased by 70-80%, HC by 70-100%, and CO2 by 50-60%. Contrary to popular belief, speed humps increase noise levels. Braking may generate noise, especially with larger vehicles, traversing the hump may create noise, especially with goods vehicles and accelerating after the hump generates more noise than a vehicle travelling at a constant speed.

Repeatedly traversing humps causes long-term damage to vehicle components, especially the suspension; and humps can cause damage to the bodywork of large vehicles such as buses, and to the underside of cars with low ground clearance. The impact of vehicles traversing a speed hump sends shock waves through the ground. Depending upon the nature of the soil, the proximity and construction of buildings, the weight of vehicles, and the frequency of traffic, these shock waves may cause structural damage to nearby properties. If you don't believe that, read the official UK regulations stating where humps can be installed - they specifically exclude anywhere within 25m of bridges, subways, or tunnels.

Drivers watching out for humps are distracted from watching out for more serious hazards. Humps may cause traffic to divert from a good road to one which is far less capable of carrying the traffic safely, this increases overall accident risk. At night, humps cause headlight beams to rise. This dazzles oncoming traffic, and in residential areas causes annoyance to occupants of houses ahead of the vehicle. Humps cause unnecessary discomfort to passengers.

The Department for Transport has written to every council in England and Wales, asking them to consult emergency services before installing more humps in response to the research by the London Ambulance Service (LAS). The LAS has concluded that up to 500 people die in the capital every year if crews responding to emergency calls are delayed by just a minute. The survey showed that a significant number of drivers took detours to avoid humps, and because of jolts caused by them, staff delayed procedures such as inserting intravenous drips. The department's letter says: "The department acknowledges that full consideration should be given to the wider implications of introducing traffic-calming measures on our roads. This is particularly important with regards to response times for the emergency services.''

Sigurd Reinton, chairman of the LAS, said, "By installing more humps we may prevent more road deaths, but it is possible that we end up paying with many lives lost.'' Barnet council in north London has already begun removing road humps, after deciding that there was no proof that they improved safety. Sixty of the borough's 500 humps have been taken away as roads have been resurfaced. Brian Coleman, a Barnet councillor, said, "I hope this warning prompts other councils to follow our example.'' He added that many disabled people as well as cyclists had objected to the humps.

Road humps vary in style, cost and effectiveness. The most expensive, the "speed table", can cost up to £10,000 each. This allows motorists to maintain a reduced but constant speed. The inflatable hump allows a car travelling slowly pass over without disruption. But a car hitting it at speed will bounce. The "round top", which costs between £1,000 and £2,000, is considered to be the most damaging to vehicles. The "speed cushion", which consists of Tarmac squares and costs £500, is placed in the middle of each lane, enabling wider axles to straddle them.

Next >>>