An overturned tractor-trailer is causing major delays on the northbound New Jersey Turnpike in Middlesex County.

The crash is in the truck lanes just south of Exit 8A in Cranbury, where traffic is backing up for miles.

There also appeared to be construction activity in the area, although it is unclear whether that had anything to do with the crash.

State police are at the scene, and trucks are being directed into the car lanes to get around the incident.

There may have been another vehicle involved, but that has not been confirmed.

There is no word yet on injuries or what caused the tractor-trailer to overturn.

Drivers heading north should use the car lanes until the crash is cleared.