With the advent of self-driving cars, in the works and due to arrive, what about adding this feature, to be used as a “special tool” for criminal investigations?

Every new car to have on board a “black box,” its function to periodically identify itself with its license plate number to all other cars in proximity (say 50 feet). The “black box” is both a transmitter of its own license plate number and a receiver of other cars’ license plate numbers only.

When the transmitting car transmits its license plate number it records internally its GPS coordinates and also recovers time of day. This internal data is for criminal investigations.

Likewise, when the receiving car receives the transmitting car’s license plate number, it records the license plate number and records its own GPS coordinates and also records time of day.

Also, so as to minimize satellite data traffic for GPS coordinates, those coordinates are only periodically downloaded to the “black box.” And subsequent coordinates are calculated from the car’s instantaneous data (velocity, acceleration, travel direction, and elevation) as the car is moving (download time interval say once an hour).

The “black box” is to be interlocked so as to defeat tampering, i.e. car won’t start. This “special tool” must be certified as to accuracy, so as to be used as prima facie evidence at trial. It is an objective tool and not subject to witness error or bias. And actually corroborates eyewitness accounts. A wholly new branch of forensic investigations is envisaged.

When fully developed this will be a powerful tool.