You can thank wireless technology for the new traffic control measure.
The city has put a series of sensors in the pavement to measure how fast a car is going, the Philadelphia Inquirer reported on Tuesday.
Two electronic signs warn drivers that "Speeding Triggers Red Light," and officials say the sensors are spaced in a way that allows drivers enough time to brake for the light.
The Inquirer said the speed limit on Kelly Drive is 35 mile an hour, but motorists drive almost 55 on average.
The street chosen for the $11,050 pilot project is the scene of frequent wrecks, the report said. And if the experiment is successful, it could be expanded to other city streets where speeding is a problem.