July 30, 2002

A Black Box for Your Car

Event data recorders could make cars safer-and tell accident investigators what really happened.

By Howard Baldwin

When an aircraft goes down, the first thing the National Transportation Safety Board looks for is the infamous "black box." Though the term is a misnomer-there are two boxes and they're both orange-the idea of capturing what went wrong in an accident is so compelling that three companies are adapting the idea to automobiles. While the concept is intriguing, its practical application has yet to traverse several obstacles.

To create what's known as an "event data recorder" for cars, these companies plan to harness the output of the sensors that already exist to deploy airbags and control anti-lock braking systems. The recorder would use half a kilobyte of flash memory to record ten seconds of data-five seconds before the crash and five seconds after the crash. It would tally such information as speed at impact, how long the brakes had been applied, how many times the car was hit-all factors that can help determine the cause of a crash and who was at fault.

"Right now, in the world of crash investigation," says Ricardo Martinez, CEO of Atlanta-based Safety Intelligence Systems, one of three manufacturers of event data recorders, "they use the BOGSAT method. That stands for a bunch of guys sitting around talking,' coming up with their best guess."

Efforts are underway to change this. Last August, the National Highway Traffic Safety Administration ran a Ford F-150 truck into a wall at 30 mph in order to determine how accurately test units from three companies-Safety Intelligence Systems, Independent Witness of Salt Lake City, and DriveCam Video Systems of San Diego, as well as an unnamed internal recorder supplied by Ford-tracked the delta in the vehicle's velocity. The agency compared the devices against three of its own Endevco accelerometers, and found Independent Witness's device to be the closest to its baseline devices; it suggested that the Safety Intelligence Systems and DriveCam devices needed further development (see the report).

Importantly, the test proved that data from an event data recorder could provide objective evidence for crash investigations, reduce the reliance on eyewitness reports, and reveal design flaws more quickly. If Ford and Firestone had been able to gather event data on accidents involving Sport Utility Vehicle tires, they might have avoided their recent liability and public relations disaster.