It happened before 6:30 a.m. Tuesday in the eastbound lanes approaching Girard Avenue.
Police tell Action News as many as eight vehicles were involved, including a SEPTA bus.
There were no reports of serious injuries.
Traffic was down to one lane for more than an hour as police investigated and tow truck operators worked to remove the vehicles involved.
Eastbound delays of more than an hour were reported on the busy interstate. Traffic was backed up for miles for much of the morning rush hour.
All lanes were finally reopened by 8 a.m.