I don't agree. You seem to be ignoring the laws of physics. The total energy dissipated in an accident is the sum of the contributions from both vehicles. If you can prove you are going only 5 miles over the limit, then it would be easy to determine how much energy your vehicle contributed to the total. The remainder has to be from the other vehicle, and at this point, it would be obvious how fast that guy was going.

On your second point, as I said in my first post, there has to be proof the data is accurate. If your vehicle has a history of malfunctions that would affect this accuracy, then it's value is questionable.

One sided Truth can be a very bad thing, especially in traffic accidents.

Let's say that one driver is going 5 miles over the speed limit, has an air bag computer.

The other driver in an older vehicle is going 30 miles over the speed limit. No air bag. And he or she does something that actually causes the accident.

In this scenario because you only have data from one driver, you could decide that the 5 mile per hour offender was at fault.

Another issue that I have. I've recently bought a new car, and it has had LOTS of problems with it's air bag computer. Took 4 tries to get it fixed. If I had an accident, and data from a clearly defective unit was used against me I would be rather upset.

So long as it can be established that these things capture data accurately, I think they're a good thing. How could the objective truth be otherwise?

This isn't all that new, but it is still interesting. There was an article on this in the Toronto Star back in Jan 2001 (here's a Risks Forum reference to it - http://catless.ncl.ac.uk/Risks/21.23.html#subj7 ).

Although it isn't mentioned in this reference, I understood that the Ontario Provincial Police had been in the forefront of developing the software, since they were aware of the data early on, but had no tools to analyse it.

As I recall, this can potentially cut both ways. A left-turning driver was struck at an intersection. Normally he would be at-fault, but he claimed that the other vehicle was travelling at a high rate of speed. Because the other car's airbags had deployed, the EDM held the information about the other vehicle's speed. It was retrieved (under warrant) and showed that the vehicle had been travelling at an acceptable speed, thus exhonerating the EDM's owner.

Separate from this, I don't think you can get away from such devices. The car manufacturers need them for info against frivolous "your airbag hurt me" lawsuits. Chalk up another unintended side effect of the litigious society.