What is the first thing they search for, besides survivors, after a plane crash? The black box, or flight data recorder. It contains all pertinent information for the 20-30 minutes before the crash to help investigators determine its cause. With that information, action can be taken to prevent accidents.
But did you know your car may also contain a black box?
It is called the Event Data Recorder, or EDR. And the first one appeared on the 1997 Chevrolet Corvette. Since then, event data recorders have been added to an estimated 15 percent of the cars and light trucks, according to the Alliance of Automobile Manufacturers.
All current model General Motors and Ford products have them. Nearly all Chryslers do, too. And some imports. Roughly two-thirds of current model-year vehicles come with EDRs.
The proliferation of event data recorders has not escaped the attention of the government. The National Highway Traffic Safety Administration published a notice of proposed rulemaking that would standardize EDRs so the data they record would be in a common format, the components would survive a crash and the information in all owner's manuals would be the same.
What is the event data recorder?
In truth, it is not like those on airplanes, and there isn't one under the seat. The EDR is a function of the air-bag controller. The air-bag system gets information from sensors and switches including an accelerometer, the brake light switch, seat-belt latch switch, throttle position sensor, speed sensors and so on to decide whether to set off the bags. The modules capture about the last 8-10 seconds of such data before a crash, or impending crash, and up to 300 milliseconds, about the time it takes to blink an eye, of information during the crash.
By the way, every time there is an impending crash, based on the system's software to detect one, the previously recorded data are overwritten. If there is a crash, the data are moved to memory, where they cannot be overwritten.
The black box on an airplane has just one purpose--to reconstruct the cause of a crash. That is why it records large amounts of in-flight data, including cockpit conversations. Automotive EDRs, on the other hand, are an integral part of the system that controls the air bags and other restraint components such as seat-belt pretensioners.
Event data recorders don't snoop on your daily driving. They don't know that you went golfing when you told the boss you were sick. They don't record conversations or the date or time of day. They don't even record your speed except in the few seconds before a crash.
The carmakers built the recording capabilities into their vehicles to test their own safety measures and use the data to improve the crash-worthiness. The Insurance Institute for Highway Safety and NHTSA run crash tests on cars and use the data to better understand what happens in a crash. The data supplement field investigations of accidents.
There are myriad benefits to event data recorders.
First, of course, is that the information may help auto companies build safer cars. It also could lead to safer roads. If the same kinds of accidents and driver reactions occur at a particular location, better road surfaces, slower speeds or better signs may be in order.
A large database of vehicle information could be compared to injury information, which could lead emergency-room doctors to check for internal injuries consistent with various types of crashes. When coupled with an automatic notification system such as OnStar, emergency medical techs may be able to respond quicker. According to the Alliance of Automobile Manufacturers, "getting paramedics to crashes nine minutes sooner can save an estimated 1,000 to 3,000 lives per year."
But what about privacy?
Carmakers, especially those belonging to the alliance, which comprises BMW, DaimlerChrysler; Ford, GM, Mazda, Mitsubishi, Porsche, Toyota and VW, advocate that the data are the sole property of the vehicle owner. Permission would be required for anyone, even the carmakers, to see them.
If the data are compiled for research or other reasons, there must be no way of tracking any back to individual cars or owners, according to the carmakers. Mitsubishi, for instance, has told NHTSA that it believes government should set regulations for EDR data usage to protect privacy.
Consumers Union, which publishes Consumer Reports magazine, presented several concerns to NHTSA including the fact that insurers may want to require event data recorders as a condition of coverage then use the data in crash-related litigation. There have been instances of the data being subpoenaed for court cases.
If you want to know whether your car has an event data recorder or more about it, read your owner's manual. It is probably in that little black box called the glove compartment.
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Recorders by the book
Check your owner's manual for information about the event data recorder on your car. Here, in part, is what a typical GM manual states:
"Some information . . . is stored in a crash or near crash event by computer systems commonly called event data recorders [EDR].
"In a crash or near crash event, computer systems, such as the air-bag Sensing and Diagnostic Module [SDM] in your vehicle may record information about the condition of the vehicle and how it was operated, such as engine speed, brake applications, throttle position, vehicle speed, seat-belt usage, air-bag readiness, air-bag performance data and the severity of a collision."
-- Bob Weber
Bob Weber is an ASE-certified Master Automobile Technician, having recertified every five years since 1978. Contact him at motormouth(underscore)email@example.com.