It happened just after 8:30 a.m. Tuesday at Mile Marker 337, near the Belmont Avenue exit, and created major delays for the morning rush.
Traffic was at a standstill between Conshohocken and Belmont Avenue.
An ambulance had to back up in the wrong direction to get out of the backlog.
There were restrictions on the westbound Schuylkill Expressway, as well.
No injuries have been reported.