Rapid response vehicles considered 'high risk' plus immediate and armed response units are to be fitted with the systems. The force decided to take action because of the high rate of accidents among police vehicles, with 5,710 crashes in 1998. The vehicles cover more than 65 million miles a year and answer 1.5 million emergency calls annually
The units will record a vehicle's speed and acceleration, whether the siren is operating and whether warning lights are being used. It can analyse information from and create a 3D 'film' that shows the car's movements before an accident.
The investment coincides with another hi-tech project which will fit all Met Police vehicles with tracking systems, allowing headquarters to monitor their fleet more effectively.
The decision to use the VDO Kienzle system followed its widespread use in Germany, where the Berlin police reported a 20% drop in accidents after fitting the devices.
Richard French, fleet engineering manager for the Met Police, said: 'The system will be fitted to 800 new vehicles this year and retro-fitting to the rest will begin next year. Within three years, the entire liveried fleet should have the devices. It should not cost us anything, because we expect to more than save the purchase cost through reduced accidents.'
The announcement will add to calls for fleet cars and vans to be fitted with the safety devices as standard. Both the Royal Society for the Prevention of Accidents and road safety organisation Brake have said so-called 'spies in the cab' would stop drivers taking risks and prevent employers from making staff work excessive hours.