SPEED bumps that flatten for motorists travelling within the speed limit are about to be introduced across Britain.

The high-tech humps have been tested on a busy road in the City of London for the past three years. Now Dunlop Transcalm, the British company that manufactures them, says that it is negotiating with several local authorities to replace unpopular static humps.

About 1,000 of the first Transcalm humps are expected to appear in London and Birmingham by early next year. The company claims that the device will revolutionise traffic calming, particularly in residential areas, on bus lanes and near schools and hospitals.

Although the new humps will hinder speeding drivers, they will reduce delays for the emergency services, which say that static humps cost lives. The smart hump is also expected to eliminate other problems. Residents on roads with humps complain about the noise and pollution caused by stop-start driving, and motorists complain about damage to cars and increased fuel consumption. Research shows that roads with static humps have 80 per cent more carbon monoxide emissions.

The only disadvantage is the cost. Each smart hump costs between £2,500 and £4,850, which the company claims is comparable to some static humps, but which motoring groups argue is double the average cost of a standard “sleeping policeman”.

That did not stop the Corporation of London trying the device. Joe Weiss, Highways and Transport director, said: “In three years not one complaint was made either from a motorist, pedestrian, cyclist or neighbour.”

The smart hump was designed by Graham Heeks, a British engineer who dreamt up the concept after examining squeezable children’s toys.

Dunlop Transcalm developed the device in association with Cambridge University. It can be customised to suit different speed restrictions and to allow larger vehicles such as ambulances, fire engines and buses to pass without delay.

The hump has a rubber canopy filled with air and a pressure valve attached that determines a vehicle’s speed. The valve opens for vehicles travelling within the speed limit, allowing the hump to deflate, but locks if a vehicle is travelling too fast.

“What we’ve developed is the first traffic calming solution to offer a carrot and stick approach, rather than the traditional stick approach irrespective of a motorist’s speed,” Mr Heeks said.

The device has been broadly welcomed by motoring organisations. The RAC did a survey asking motorists what three things they would like to change about driving today. “At number two was remove speed bumps,” said Paul Hodgson, an RAC spokesman. “I think that if this new device does what it says it does then it will solve many of the problems that drivers have with speed humps, such as noise, car damage, pollution and use of fuel. The only downside is the cost, which means its use will probably be limited.”

Paul Watters, of the AA Motoring Trust, said: “Speed humps are disliked by motorists, but they do the job they are meant to. They reduce speed, calm traffic and reduce accidents. But for the average driver this device is preferable to the traditional hump, particularly on bus routes.”

IN THE ROAD

There are three speed hump designs: the original “sleeping policeman”, which has a rounded top; the “speed cushion”, a raised square in the middle of a lane; and the “speed table”, a wider, flat-topped hump