Despite being the oldest in the city, the red-light cameras at Grant Avenue and Red Lion Road along Roosevelt Boulevard are not the most ticketed. Image/Google Maps

Philadelphia’s most ticketed red-light camera is at South Broad and Penn Square, just south of City Hall.

Though Center City is one of the busiest areas of the city, its cameras were installed a full four years after the ones at the Red Lion Road and Grant Avenue intersections of Roosevelt Boulevard. So why are there more violations at the newer cameras?

Aside from being high-traffic areas, the Center City red-light camera intersections still surprise some drivers. According to AAA Mid-Atlantic’s assessment of Red light camera a Pennsylvania State Transportation Advisory Committee report, red-light camera violations typically decrease at an intersection over time, dropping nearly 50 percent after the first year.

A map of Philadelphia’s red-light cameras, compiled by NewsWorks:

View Philadelphia’s red light cameras in a larger map

A study of accidents for the 10 red-light camera intersections that have operated for at least three years in Philadelphia found a 66 percent reduction in fatalities, and a 24 percent drop in injury crashes.

“It costs, on average, $31,847 per month to operate each red light camera intersection in Philadelphia,”  according to AAA Mid-Atlantic. “Given a $100 fine per violation, each intersection needs to generate about 10.5 violations per day, about 318 per month, to cover operational costs.”

Philadelphia’s red-light camera program will continue through at least 2017. Three additional cameras will soon be operating in the Far Northeast, and a fourth is on the way.