Responsible drivers should not be punished for travelling within the speed limits

Mike Armstead Dunlop

The Transcalm hump should not only make driving easier but reduce neck injuries and cut noise levels say its developers, who are road-testing it in the City of London.

But not everyone is convinced.

Brian Simpson, of the Campaign Against Road Hump Madness, said: "The new design could be better for a single vehicle going over in isolation but that is not how it works in practice.

'Humps lead to frustration'

"While road humps may slow traffic on certain streets, they usually push drivers on to other roads, which may become more dangerous, and lead to frustration and drivers speeding elsewhere to try to make up their speed."

The hump was invented by Graham Heeks and developed in Manchester by Dunlop GRG and highway consultants Pell Frischmann.

Got the hump?

The first traffic humps appeared in the 1970s There are about 50,000 in the UK The Dutch round-top hump is the most common The squarer flat-topped hump became popular in 1990 The sinusoidal hump has a gentler angle to reduce discomfort Thumps are hard, triangular, thermoplastic strips German speed cushions are put across roads in twos or threes to slow cars but not buses or emergency vehicles

The air-filled hump is made of rubber and has a valve fitted which can control the rate air escapes when vehicles drive over it.

At higher speeds the Norgren air valve closes and the motorist will encounter a solid hump, similar to conventional road bumps.

But for drivers travelling at the designated speed - which can be set between five and 30mph - the valve opens and the hump deflates.

Mike Armstead, chairman of Dunlop Transcalm, said: "The concept was based on the basic premise that responsible drivers should not be punished for travelling within the speed limits.

"Ambulances with casualties and delicate equipment on board have to slow to 3-4mph to go over a conventional road hump, but these will allow them to cross without reducing their speed."

If the current tests in Puddle Dock Street, near Blackfriars station, are successful the manufacturers hope their new humps will be rolled out across the country.