On Tuesday, a Council committee approved two more cameras, at the North and South Broad Street intersections with the City Hall square.
Motorists who run red lights can trigger a $100 fine. Generally, the vehicle owner is mailed the citation, which imposes the fine but no points.
Chris Vogler, manager of red-light photo enforcement for the Philadelphia Parking Authority, answered some questions about how the Philadelphia program works:
What if a driver runs a yellow light?
The driver should not receive a ticket, Vogler said. The camera takes pictures only after the light has turned red and sensors indicate that a vehicle has crossed the wide white line, or "stop bar," painted on the road before the crosswalk.
A built-in delay of 0.3 of a second gives drivers a little grace period, Vogler said. Problems with the delay last year resulted in the authority's refunding or dismissing fines for more than 4,000 tickets.
What if the vehicle stops but has nosed into the intersection?
The cameras take two pictures, one after the other. The first is snapped 0.3 of a second after the light turns red if a vehicle is detected past the stop bar. The second picture shows whether the vehicle continued into the intersection. Examiners check the pictures, and if they see a vehicle in the intersection, they issue a citation. If the vehicle only nosed past the stop bar, the examiner might ignore the infraction.
"If a car's blocking the crosswalk, that's a hazard to a pedestrian," so the car owner could get a ticket, Vogler said. The program came about in large part because of concerns about pedestrian injuries and fatalities, he said.
What if a driver turns right on red?
