Some 500 video cameras mounted on signal poles provide traffic count data, which is used to calibrate signal times for some 1.5 million cars on a daily basis…
The system is also designed for more than cars. Special sensors in the pavement know when a bicycle pedals up to an intersection. The sensors can trigger a change in signal timing to give the cyclist an adequate amount of time to make it through the intersection. “You hear a lot about smart cities and bike lanes, but we started this about 12 years ago,” said Prasad.
Then there are the pedestrians who are trying to walk across 10 lanes of traffic. “These are very large intersections” Prasad explained. “In order to provide them sufficient time we use microwave sensors. That microwave sensor is actually tracking pedestrian movement in the crosswalk. And when the crossing time is about to end, if it still detects a pedestrian, it can provide them an extension.”