One person has been killed and another has been critically injured following two very similar but separate crashes early Friday.

One collision before 5:30 a.m. involved a transport truck and a car on Wellington Road 86 near Ariss, northwest of Guelph.

OPP say a northbound Pontiac Grand Am crossed the centre line, hitting the truck and causing it to jackknife.

OPP Const. Mark Cloes says the 45-year-old, "A Burlington resident was taken to hospital where he was pronounced deceased in this collision."

The driver of the truck, 34-year-old Michael B. Hurst of Palmerston, Ont. was not injured.

The road remains closed as OPP continue their investigation.

Meanwhile fire crews from Conestogo and Elmira were called in for a serious two-car crash on Northfield Drive East at Jigs Holllow Road shortly before 9 a.m.

A northbound silver car driven by a 35-year-old woman from Waterloo reportedly crossed the median striking a southbound maroon van driven by a 63-year-old Elmira man.

Waterloo Regional Police Sgt. Frank Heinrich One says "There was one occupant in each of the vehicles. The one occupant that was travelling northbound was transported to hospital with major injuries, and the driver of the southbound vehicle was also transported to hospital."

Waterloo Region police closed Northfield between Scotch Line Road and Jigs Hollow Road for about eight hours after the incident.

Police say both crashes are still under investigation and it is still too early to say what caused the accidents.

However, they are warning drivers to be aware of the changing weather conditions and to ensure they have good visibility and leave extra time to get to their destination.