If you motor through the busy intersection at Broad and Vine Streets, be forewarned: Philadelphia's newest red-light cameras were to be be activated there at 12:01 a.m. Monday.

That brings to 20 the number of high-risk intersections equipped with devices to catch - and penalize - red-light runners.

Violators will receive warnings for the next 60 days; beginning Dec. 2, the fine will be $100.

"These new cameras will help protect all pedestrians, such as the students that attend Roman Catholic High School," Philadelphia Parking Authority executive director Vince Fenerty said in a statement. "From now on, people will think twice before speeding up Broad Street to make a light."

Philadelphia is the only place in the state allowed to have the "gotcha" cameras, although legislation has been introduced in the House of Representatives to expand the program to other Pennsylvania cities.

Philadelphia's revenue from fines is split 50-50 between the city and the state, which distributes it to municipalities for transportation projects. For this fiscal year, which ended March 31, the 141,571 citations issued to Philadelphia scofflaws yielded $7.6 million, according to the latest Parking Authority report.

That sharing system may also be challenged. State Rep. Michael McGeehan, ranking Democrat on the House Transportation Committee, has said he plans to introduce legislation to extend Philadelphia's program beyond this year, when it is set to expire, and keep the revenue from fines where it was collected.

Red-light runners cause hundreds of deaths and tens of thousands of injuries each year, according to highway safety authorities. A recent study by the Insurance Institute for Highway Safety concluded that red-light cameras had reduced the rate of fatal crashes by 24 percent in 14 cities nationwide that introduced them between 1996 and 2004.

Some critics have argued that longer yellow-signal timing would be more effective than cameras. But a study by the Institute of Transportation Engineers found that lengthening yellow lights by about a second reduced red-light violations by only 36 percent; camera enforcement was found to be far more effective.

Philadelphia's program has brought in about $28.4 million in fines since it began in 2005. The Parking Authority used about $15.4 million of that to cover equipment and administration costs associated with the program.

The first cameras were installed at Grant Avenue, Red Lion Road, and Cottman Avenue along Roosevelt Boulevard in the Northeast. Since then, intersections have been equipped in South Philadelphia, West Philadelphia, and Center City.

Contact staff writer Marie McCullough at 215-854-2720 or mmccullough@phillynews.com.