A 30 year-old Guelph man is dead following a two-vehicle crash on Highway 401 at Guelph Line in Milton.

The collision happened in the wee hours of Thursday morning and closed parts of the highway for a few hours. All lanes of the highway have since reopened. 

Police say that a car collided with a tractor-trailer just after midnight near Guelph Line. The 30 year-old man was pronounced dead inside the car when paramedics arrived at the scene. 

The Ontario Provincial Police are still investigating the cause of the crash. The westbound lanes were closed for a number hours after the crash. 

A separate crash around 1 a.m. on Highway 401 near Highway 6 closed the artery's eastbound lanes as well. It involved a truck colliding with a car and rolling over into the centre rail.

Light snow and freezing rain may have been a factor in both collisions, police say.