One person has been taken to hospital with life-altering injuries after a serious crash near Cambridge.
Traffic ground to a halt along the westbound 401 near Cambridge Thursday morning after the early morning collision.
Ontario Provincial Police (OPP) officers were called to the crash west of Homer Watson Boulevard involving a transport truck and a car around 4 a.m.
The driver of the car was taken to a trauma centre with serious injuries.
Traffic continued to move slowly through the area during the morning commute.
Police said all westbound lanes of the highway were closed at Homer Watson during the investigation. OPP said all lanes reopened at 12:29 p.m.
This is a developing story.