A camera to catch HOV lane cheaters

From the Evening Standard: Camera that can catch lone drivers in car-sharing lanes.
This has always been a difficult problem for authorities, as enforcement has in the past required human eyeballs. Researchers have experiment with infra-red to determine the heat profile inside the car, but that was apparently problematic. But in the home of the panopticon, cameras (with appropriate recognition systems) will be able to identify the number (and apparently race) of passengers in the vehicle.