The lanes were opened at 1:00 p.m. Tuesday after being shut down in both directions for more than four hours.
The crash happened at 8:46 a.m. in the area of Cedar Hollow Road.
Five vehicles were involved in the wreck, some of which broke through a temporary Jersey barrier separating the northbound and southbound sides.
Chopper 6 HD was over the scene shortly after the crash happened. A large commercial truck was seen lying on its side farther down the road, along with a station wagon with extensive damage to its roof and side.
There was no immediate word what caused the crash, which happened in section of Route 202 currently under construction.
Of the four people who were injured, three people were taken by ambulance to Paoli Hospital. They were expected to be treated and released.
A fourth person, who was airlifted to Reading Hospital, was listed in stable condition.