A serious collision closed all westbound lanes of Highway 401 near Ayr Tuesday afternoon.

The crash occurred around 4:30 p.m. just west of Trussler Road.

Provincial police say a car was travelling west when it hit the centre median, crossed back into traffic, and hit a transport truck. Police say the car then hit the median a second time before finally coming to a stop.

Police say the male driver of the car was taken to hospital with life-threatening injuries.

The driver of the transport truck was not hurt.

All westbound lanes of the highway were closed at Cedar Creek Road for several hours.

Police are still trying to determine what may have lead to the crash but they say wet weather conditions were causing delays in their investigation.