The eastbound collector lanes on Highway 401 at Avenue Road have reopened following a single-vehicle crash Tuesday morning.
Ontario Provincial Police said a vehicle rear-ended an excavator, which was located in a construction zone on the right shoulder of the highway.
Sgt. Kerry Schmidt said a 47-year-old woman was transported to hospital with life-threatening injuries.
Police said the collector lanes were closed for the morning rush and reopened just after 11 a.m.