Speeders get the 'intelligent' hump.
The new hump, which manufacturers claim is the world's first 'intelligent' road hump was developed in Manchester to deflate for heavier vehicles like ambulances and fire engines, or for cars travelling under a set speed limit.
Conventional 'sleeping policemen' made from concrete or asphalt have drawn criticism for causing back and neck injuries, damaging bus and car suspension systems and increasing noise and pollution.
The new system, known as Transcalm, is made from rubber and contains a fast working air valve which can deflate the hump.
The super-sensitive valve, developed by Norgren in Lichfield, Staffordshire, is triggered if a vehicle is over a set weight limit or if it travels under a pre-programmed speed limit, which can be set between five and 40mph.
Cars travelling faster than the set limit will not deflate the ramp, which will then act like a conventional speed hump.
The system, developed over the last four years by Dunlop GRG, highway consultants Pell Frischmann and inventor Graham Heeks, begins trials in London today with a view to being introduced nationwide.
Two ramps were installed in Puddle Dock in Blackfriars, central London, where the system's success will be monitored and regularly reviewed.
Dunlop Transcalm chairman, Mike Armstead, said road humps were 'the most famous and most hated' traffic calming measure.
The world's first 'intelligent' road hump which deflates for emergency vehicles and drivers going under a set speed