One of the critical items to consider in every case is the "black box" data that many cars and trucks are equipped with. These boxes save data on speed, turn signals, braking, and other information that is very useful to determine in a wreck. Many is not all but that is soon to change. As of September 2012, NHTSA regulations (49C.F.R. 562) will require vehicle manufacturers to provide commercially available systems which can be used to retrieve event data recorder (black box) information. Moreover, the information will have to be available in a standardized format. At present, the Bosch Vetronix retrieval system is the only commercially available system. However, the Bosch system cannot be used on all vehicles.
It is still critical to have an expert and lawyer who is familiar with these systems if you are involved in a wreck. And commercially available doesn’t mean cheap, but after 2012 competent lawyers will have a much better chance of proving, scientifically and with objective proof, that their client was not at fault in causing a wreck.