Morning traffic on the Parkway West outbound was backed up for miles during rush-hour and many hours later following a crash near the Carnegie exit, state police said.
Traffic was jammed for about five hours from Carnegie back through the Fort Pitt Tunnel to the Parkway East near Grant Street following the crash, which occurred shortly after 6 a.m.
The crash involved a cement truck smashing into a barrier. No injuries were reported.
Traffic snarled inbound parkway commuters as well as those traveling in on Interstate 279, where it was backed up to the Bellevue exit.
Also, certain Port Authority bus routes were experiencing delays.
Workers repairing the barrier later had to stop traffic on the Parkway West for a few minutes, PennDOT officials said.
State police said Parkway East and Parkway West traffic was moving again by 11 a.m.