An 85-year-old woman is in hospital in critical condition after driving the wrong way on Highway 401.
Police say it happened just before 3:00pm yesterday on the 041 at Gardiners Road in Kingston.
They say her car ended up travelling westbound in the eastbound lanes, then crashed.
The other driver and passenger involved were uninjured.
The crash caused the eastbound highway to close for several hours. An investigation is ongoing.
Police also say a secondary collision happened in the slowed traffic east of County Road 4 involving three cars and a transport truck. That crash forced County Road 4 to be closed for two hours.
There were only minor injuries as a result of that crash.