Motor vehicles are getting more and more complicated as the years pass. Vehicles can now park themselves; they have rear cameras that give the driver a much wider field of vision when backing up; they have entertainment consoles burrowed in the middle of the dashboard; and, in general, cars are simply far more technologically advanced than anyone could have imagined even 15 years ago.
One newer feature in motor vehicles is the "black box," an onboard computer that records some basic data about the vehicle. New Haven residents may not know this, but the black box data is always running (though not all of it is permanently recorded) and it is particularly useful should a car accident occur.
To be fair, there are certainly some privacy concerns with the black box. The data is freely accessible for law enforcement and insurance companies, with few laws (if any) protecting the car owner or driver.
However, the black box can really help investigators -- and the victims of an accident -- put together the pieces in the wake of a violent collision. The black box records data from a small chunk of time prior to any crash. It gathers data like the car speed, how hard the accelerator or brakes were being applied and the status of the seat belts (if they were buckled or not).
Each of these factors are objective pieces of data, giving concrete evidence on a car accident. The victims of the wreck could then point to certain aspects and question a driver's decisions behind the wheel; while law enforcement could use the data to cite the driver or press charges against him or her, depending on the situation.
Source: NBC News, "Car black boxes provide crucial accident data," Tom Costello, Aug. 8, 2013