A tractor-trailer that jackknifed this morning during a crash on I-476, the Northeast Extension of the Pa. Turnpike, forced emergency personnel to shut the southbound lanes earlier this morning in Quakertown.

The lanes have since been reopened.

The crash involving the truck and another vehicle occurred between the state Route 663/John Fries Highway and state Route 63/Sumneytown Pike exits around 8 a.m.