Black boxes on cars

Wouldn’t it make sense to install black boxes on cars to record their behavior in accidents? After all, the accelerometers already exist to trigger airbags, The computer already monitors speed, engine rpms,and on cars with antilock brakes, the angular velocity of the wheels. It seems to me to be a simple and inexpensive matter to tie these factors together to exactly recreate what happened in an accident. This data would be most usefull in the design of safer roads and cars as well as identifying certain human errors which could be useful in for educational purposes.Such data would also be useful in determining liability with mathematical precision.

The philosophers have only interpreted the world in various ways; the point, however, is to change it. (Karl Marx, 1845)

It wouldn’t do much for recording the stupidity of the vehicle’s driver.

What good is half a$$ data?


For the most part, we know what causes automobile accidents and we know what parts of our highways aren’t safe.

If the car has some sort of mechanical defect, can’t that be discovered by examining the wreckage?

Also, automobile accidents tend to have eyewitnesses and most people walk away from them. That usually not the case when a plane crashes.

Often better than no data at all. How else can I prove that the guy who rammed into my car was doing 30 mph above the speed limit?

I heard of such devices parents can install on their teenagers’ cars to monitor their driving habits. It’d be hard to mandate it for everyone though. Even if it weren’t for privacy advocates, the cost of installing one on every single car on the road is prohibitive. And if it was optional, how many people would install one?

Speed recording devices are mandatory on heavy vehicles in a couple of Australian states, as a gut-reaction by governments concerned about a spate of accidents that involved large buses, trucks and semi-trailers.

Much of the heavy transport in Australia carries federal registration, as opposed to state plates. With the recent adoption of national road rules, the highway speed limit for these vehicles is now 100km/h.

IIRC, it is now a requirement that heavy vehicles must be fitted with a speed recorder, or a governor fitted to the engine/transmission.

No-one has put forward a case for similar laws to be applied to passenger cars yet, but as with all politicians looking for votes, anything is possible…

Knock softly but firmly, 'cause I like soft firm knockers…

Speed recording devices are required on European trucks and buses as well - not only to keep their speed down, but also to make sure that the drivers comply with the rules for driving & resting. This might sound a bit Orwellian, but our roads are crowded, and the brakes on most trucks and buses are frankly the pits. The couple of truck drivers I know (my sister used be one) are not at all unhappy with the installations - it saves them a lot of arguing with their bosses.

And politicians are now wondering how they can be applied to private cars: The buzzword in some circles right now is “road pricing”: a GPS navigator in each car keeps a record on the roads used and adds up the fees for using the specific roads. “No record will be kept of where the car has been” - yeah, sure. Of course, another smart-alec thought this could be used as a high-tech speed governor, keeping the car within the speed limits at all times. (I’m not making this up).

Luckily, it seems to be on the way out again, as the invovlved politicians are realizing that this is about the safest way to get kicked out at the next election.


Some years ago, an experienced (U.S.) federal highway safety engineer pointed out to me how relatively simple and inexpensive it would be to collect good crash data by equipping cars with black boxes. His concern was not so much with knowing the cause of each individual crash as with learning how vehicle characteristics contribute (or fail to contribute) to the risk of crashes. This was about the time when antilock brakes were coming onto the market and it appeared that while cars with antilock brakes were involved in fewer head on collisions they were rolling over more often than similar cars without antilock brakes. If cars had black boxes his job, figuring out whether the antilock brakes were contributing to the rollovers or not, would have been easier.

The highway safety engineer didn’t tell me why he thought cars didn’t come with black boxes but several reasons come to mind, some already mentioned.

Cost: With the huge number of cars purchased new in the U.S. each year, even a $10 device would cost consumers millions of dollars.

Orneriness: Americans hate any abrogation of their “right” to break the law and American legislators know it. (For example, the legislature of California has refused for years to let the California Highway Patrol use radar to measure speed. Another example, the U.S. is way, way behind Europe in the use of cameras to document traffic violations.)

American “justice”: It seems to me that the most skillful trial lawyers, those who can put on a show and appeal to emotions, are put at a disadvantage when the facts of a case are known with certainty (e.g., the defendant’s car was doing 156.5 km/hr at the moment of impact). They might feel that in personal injury cases involving motor vehicles, having even more facts available because of black boxes could cramp their style or worse, cost them money.

Half-a$$ data: I don’t think this is an argument against black boxes. Look at the data accident investigators work with now: measurements of the length of skid marks! reports of eyewitnesses! Compared with speed, direction, deceleration, throttle position and brake hydraulic pressure, skid marks and eyewitness accounts are half-a$$.

Ummm, cars ARE beginning to come from the factories with these black boxes. I think that any car manufactured after approx '97 had what’s called ORB-II or some such. Mainly the manufacturers use this to record data that might help in diagnosing a problem with you car, but they can also get a lot of info about your driving habits. I’m sure that if you come in with a fried up engine for warranty work, and then they look at the data that says that you regularly drive well into the redline, they could refuse to do the work under warranty. They’re also able to tell if you’ve installed any after-market parts that might also violate the terms of the warranty. Manufacturers spend A LOT of money on warranty work, so it’s well worth it for them to try and find a way to get out of doing work for free when it’s really the driver’s fault for driving the car into the ground.

As an ambulance officer who frequently attends MVA’s, I have had some involvement with the Accident Investigation Section of the South Austrlaian Police Dept.

All of the “half-assed” data to which yuou refer is actually assessed and scientifically dissected by these experts to reconstruct the exact nature of how the accident occurred.

Each of the seemingly simple indications, such as paint transfer, vehicle damage, skid marks, stretched seatbelts, interior damage (particularly evidence of bodily injury to the occupants), tells a story that can be pieced together with the other evidence.

These guys get really pedantic. When a fatality has occurred, they treat the accident site like a crime scene, and the upmost care is taken to preserve evidence.

For example, they take out the speedometer of the vehicle(s) involved and check the dial against an ultraviolet light. This will show where the needle impacted against the back of the guage, revealing what speed was indicated to the driver upon impact.

Where items break away like shrapnel, simple physics is used to calculate what speed (read kinetic energy here) was required to propel the object to where it landed.

What a black box will do is make the accident investigator’s job somewhat easier, by supplying all of the physical data. He will still need to interview witnesses, drivers and occupants to understand just why someone made an error.

Knock softly but firmly, 'cause I like soft firm knockers…

My primary concern with vehicle black boxes is, who has access to the black box information? Can the police request (systematically or at random) your data and issue speeding tickets for events they didn’t witness? Can insurance companies demand the information before you renew and use the data to adjust your rates? In event of an accident, can your entire driving history be subpoenaed and used against you in court?

Too invasive for me.

To the OP: Funny you should ask.GM Installs “Black Box” on Autos

I understand car manufacturers have two reasons for installing these devices. One, as has been mentioned, is to gather information that will allow improvements in car design but another is that it would allow better information to determine liability when drivers sue the car manufacturer. In general, it is believed it would provide information that would help prove drivers’ mistakes.

Not surprisingly, some groups oppose this because of privacy concerns but this is idiotic because if you want to sue, you should be obligated to supply as much information as possible to determine who is right. Saying “you are responsible but I will not give you the information to prove it because I want to protect my privacy, is plain stupid”.
I believe the devices are useful.

DVous Means, I didn’t say there was anything half-a$$ about what MVA investigators do with the data available to them, just that the data routinely available to them, in the absence of black boxes, aren’t so great. I also didn’t say that such half-a$$ data aren’t useful or that such data would be of no use if black box data were available.

I do think, however, that if black box data were available, it would not only make the job of MVA investigators “somewhat easier” but would also enable them to reach firmer conclusions in many cases.

Voltaire, although I am not an expert by any means, I have done some reading on the OBD-II interface of which you speak (type?). If I recall correctly, it merely provides present time diagnostic data, rather than recording any previous data.
For example, you can hook up the mechanic’s computer and see the various measurments of the engine in operation, but have no (or very limited) data about how it was operating before.