Last year the city of San Diego installed 3,200 smart streetlights, each one monitoring 36 x 54 meters of pavement. They originally used the data to time traffic signals — but now Slashdot reader Tekla Perry summarizes a report from IEEE Spectrum:
Developers for the City of San Diego spent months training its smart streetlights to recognize and count bicycles from just about any angle. The system is now monitoring bicycle traffic, but a few issues remain–figuring out how to distinguish between bicycles being ridden–and those doing the riding, like on a bike rack or thrown in a pickup truck.
The software has a similar problem with pedestrian-counting: When a convertible comes into view, it is counted as both a car and a pedestrian–the visible driver.