It happened around 1:30 a.m. on U.S. Route 1 North near the Fairless Hills exit.
A 34-year-old bicyclist was killed.
Police say they are now looking for the person who was driving a black BMW sedan which was found abandoned on the side of the road.
The car had damage to the front-end and windshield.
Investigators say they know who the car is registered to but are trying to determine who was driving at the time.
Anyone with information is asked to call Falls Township Police.