Sleeping policemen

One form of driver assistance which is sure to create a fuss is intelligent speed adaptation (ISA)—a technology for forcing the motorist to observe the speed limit. This works by building into the car a digital map marked with local speed restrictions. The addition of GPS (global positioning system) navigation tells the car what the maximum speed on any given stretch of the road should be. Cars are then slowed down , or prevented from accelerating, whenever they are at or above the speed limit. One way to do this is to starve the engine of fuel. Another is to add a measure of play (ie, slack)to the accelerator pedal. A third is to make the accelerator harder to push down. In future drive–by–wire vehicles, the software would refuse requests from the accelerator pedal when above the speed limit.