In the olden days, measuring the length of skid marks at the scene of an auto accident was a valuable forensic tool, from which you could independently verify vehicle speed after a crash. If a car leaves a 150 foot skid-mark in a 25 MPH zone, odds are he was speeding. Since the advent of ABS brakes, though, skid marks should be much less common. Does this make it harder to reconstruct the scene of an accident, or are there other tools and techniques that have become more prevalent?
Among other things, the black box which detects speed, brake light on/off status and such at time or air bag deployment is a great aid to accident reconstructors.
“or” should be “of” :smack:
Are these black boxes commonly installed in passenger cars? I know a lot of commercial trucks use them but I wasn’t aware of them being in more common usage.
No not really, plus there are also some severe privacy issues here.
Event recorders are used in cars. Some running parameters are recorded when say a check engine light is set on a modern car. Things like engine RPM, coolant temp, and O2 sensor status are recorded. These are required by law here in the states, and can be a big help to a technician.
However that does not address the issues mentioned in the OP.
Event recorders for airbags and ABS may or may not exist on a particular car. In any event it would either take a court order or the permission of the car owner to download the data.
so event recorders are not usually used in accident investigations, but they can be.
ABS brakes do leave a faint “skid” marks as the brakes are on the verge of lock up, so a proper investigation done in a timely manner can detect these and measure them. If Bubba the sheriff doesn’t do this right after the accident, a little bit of traffic will erase any evidence.