The driver of a vehicle that went off Interstate 78 near the Bernards-Warren border was trapped for hours Tuesday afternoon before finally extricated, State Police said.

The vehicle was traveling westbound near mile-marker 34 when the accident occurred at about 3 p.m.

The driver was finally extricated at about 6:30 p.m., State Police said. The westbound lanes had been partially closed during the extrication and for a medevac helicopter to land on the roadway for the injured victim, State Police said.

UPDATE: Driver in stable condition after accident.

The Liberty Corner Fire Co. had extricated the woman from the vehicle, said Liberty Corner Chief Marc Friedman.

All westbound lanes were initially closed, but the left lane re-opened at about 4:30 p.m., Trooper B. Travinsky in the Somerville barracks said.

Travinsky said the driver was the only occupant of the vehicle.

Police could not confirm the extent of any injuries to the motorist, whose vehicle rolled over and came to a stop in a wooded area off the roadway.

Patch will continue to update this story.

Linda Sadlouskos contributed to this story.