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Black boxes are already in automobiles, and your car may have one!

By: staff

Date: Sunday, 11. March 2007

One of the best-kept secrets in the auto industry is that many late-model GM cars now have electronic gizmos installed along with their airbags to record data when a car crashes. The device, much like the black box on an airplane, is known in the trade as a Sensing & Diagnostic Module (SDM), a simple version of which was first installed in the 1994 model year.

That relatively unsophisticated accident data recorder replaced the multiple electro-mechanical switches, previously used to tell the airbags when to deploy, with a single solid state accelerometer. The circuitry also computed and stored the change in velocity during the impact to provide an estimate of the severity of the crash. In addition, it recorded whether the driver's seat belt was buckled at the time.

Certain GM cars in the 1999 model year have the added capability to record vital information for a few seconds prior to impact. Vehicle speed, engine RPM, throttle position, and whether the driver was braking or not are recorded for the five seconds preceding a deployment or near-deployment of the air bags.

This latest SDM is installed in the 1999 Buick Century, Park Avenue, and Regal; the Cadillac Eldorado, DeVille, and SeVille; the Chevrolet Camaro and Corvette; and the Pontiac Firebird. Almost all GM vehicles will receive this capability over the next few years.

The airbag black box was first publicized at an International Symposium on Transportation Recorders held in Arlington, Virginia in May 1999. The SDM is, in fact, invaluable to crash investigators who, until now, could only take an educated guess at the speed of a car involved in an accident based on evidence at the crash scene.

Doctors, engineers and government officials say the information can help them better understand how the human body tolerates car crashes. They plan to apply that knowledge to build safer cars, improve the treatment of crash victims and formulate safety standards to give better protection to passengers.

But the existence of the black box is also raising sensitive privacy questions about whether such information can be used in litigation.

The symposium heard that General Motors is currently the only manufacturer that makes such data and a tool to recover it available to researchers. GM hopes to have laptops available by the end of 1999 so government crash investigators can download data independently of the company.

Bob Lange, director of engineering safety for GM, said at the symposium that he wanted to use the device to collect crash injury information from all age groups so that cars could be designed to further "reduce the likelihood of injuries."

A technical paper presented at the symposium concluded that "on-board vehicle recorders have the potential to greatly improve highway safety by providing regulators, vehicle manufacturers, and other researchers with objective data on vehicle crashes and pre-crash scenarios.

"Well-coordinated efforts by all parties sharing highway safety responsibility will be needed to achieve the results envisioned when the NTSB issued its recommendation for cooperative efforts to utilize crash recording technology," the paper added.

Quoted by Associated Press, John Hinch, a research engineer at the National Highway Traffic Safety Administration and one of the authors of the paper, said he saw "lots of potential" for the module's data.

"If we can understand crashes better, we can have better sensors [in automobiles], better air bags," Hinch said. "NHTSA can build better [safety] rules and have better information for consumers."

Insurers also seem to favor so-called black boxes for cars, in part because they would help them determine who is at fault in accidents. But they say courts will first have to sort through how such devices could be used in litigation and whether they are reliable.

Apart from supplying vital information in the wake of a crash, on-board computers can actually play a role in accident prevention, as was demonstrated by a six-month case study involving two groups of school buses in the U.S. The first group was fitted with a computer system that recorded such data as driving time, road speed, distance traveled, and engine load. The second, or control, group with no black box installed experienced 72% of total accidents.

Undoubtedly, the drivers who knew they were being monitored took greater care. Not only that, fleet managers can use the information to give additional training to drivers with registered shortcomings.

It's unfortunate that technological developments appear increasingly to impinge on our personal freedom. However, when it comes to saving lives, perhaps we should not put too high a price on that freedom.

Related Article:
International Symposium on Transportation Recorders May 3-5, 1999 Arlington, Virginia.

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All Comments (8)

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They who can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety.
Benjamin Franklin

A Wright,

@ Walt Kelly
I agree, the constant thing over cars really irritates me! As long as there are people driving, there will be accidents, and as the human body isn't designed to go any faster than 20-30 km/h, there will contiue to be fatal accidents. The only way to stop it is stop people driving or get a computer to do it all. And even then you can expect to have people die from computer errors.

dicky wolf,

this is false

Walt Kelly,

We should put a very high Price on freedom!!!!


what all does this do??


What if somebody comes to your house to give you a lot of money, and you aren't home? What then?


Turn ignition off Simple


Not about black boxes. Your driving down the highway at 60 mpg with a passenger, your car is in cruise control, you have a center console and the button to turn off the cruise control is on the left side of the steering wheel. You pass out, what does the passenger do to control the car and bring to a stop. How about it NTSB, work on this one.

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