Rich0 writes "In a new twist on traffic speed enforcement, The Times is reporting that Britain is piloting a new device which will use GPS to actively prevent speeding. The device will initially be offered in conjunction with discounts to the London congestion surcharge." From the article: "A study commissioned by London's transport planners has recommended that motorists who install it should be rewarded with a discount on the congestion charge, which tomorrow rises to £8 a day. The trial Skodas were fitted with a black box containing a digital map identifying the speed limits of every stretch of road in Leeds. A satellite positioning system tracked the cars' locations. "