The eastbound lanes of Highway 401 have re-opened after a crash on the highway between County Road 42 and Queens Line in Chatham-Kent.
The OPP say a collision occurred at about 12 p.m. Monday when a passenger vehicle struck the rear of a tractor trailer both travelling in the eastbound lanes.
The driver of the vehicle was transported to hospital with life-threatening injuries.
The driver of the tractor trailer was not injured.
The OPP's Technical Collision Investigators have been on the scene for most of the day.