Private companies in the Washington D.C. area are considering building separate lanes for fee-paying drivers, but they'll need a method of differentiating paying solo drivers and carpoolers. One option is to install infrared scanners that can detect the number of people in a car. That means anyone thinking they could get away by putting a fake dummy in the passenger seat had better think again.
It's estimated that one out of every five cars using car pool lanes in Virginia has only the driver inside, which has this scanner idea receiving strong support from both authorities and private individuals. Privacy advocates are wary that the scanners could actually identify individuals' faces and be used by the government to monitor a person's movements, but the makers of the system are designing them so that faces are obscured.
[Source: The Wahington Post via Winding Road]