<P> There are many different patents related to various types of EDR features . </P> <P> The Eaton Vehicle Onboard Radar (VORAD) Collision Warning System is used by many commercial trucking firms to aid drivers and improve safety . The system includes forward and side radar sensors to detect the presence, proximity and movements of vehicles around the truck and then alert the truck driver . When sensors determine that the truck is closing on a vehicle ahead too quickly or that a nearby vehicle is potentially hazardous, the VORAD system gives the driver both a visual and audible warning . The VORAD system also monitors various parameters of the truck including vehicle speed and turn rate plus the status of vehicle systems and controls . The monitored data is captured and recorded by the VORAD system . This monitored data can be extracted and analyzed in the event of an accident . The recorded data can be used by accident investigators and forensic engineers to show the movement and speed of the host vehicle plus the position and speeds of other vehicles prior to the incident . In accident reconstruction, the VORAD system is a step above the EDR systems in that VORAD monitors other vehicles relative to the host vehicle, while EDR's only record data about the host vehicle . </P> <P> Event data recorders were introduced to American open - wheel championship CART in the 1993 season, and the Formula One World Championship in 1997 . This allowed to study crashes that allow to develop new car rules and track safety measures that reduce damages . </P> <P> Usage of the device in road vehicles once varied widely from manufacturer to manufacturer, but EDRs are now mandated in all new vehicles . As of 2003, there were at least 40 million vehicles equipped with the devices . In the UK many police and emergency service vehicles are fitted with a more accurate and detailed version that is produced by one of several independent companies . Both the Metropolitan police and the City of London police are long - term users of EDRs and have used the data recovered after an incident to convict both police officers and members of the public . </P>

What year did they put black boxes in cars