All Fort Erie-bound lanes of the Queen Elizabeth Way near Dorval Drive in Oakville were closed overnight after a female pedestrian was fatally struck.
It happened just before 10 p.m.
Ontario Provincial Police Const. Taylor Konkle said the pedestrian was hit by a transport truck.
The victim was taken to a trauma centre in Hamilton. Police initially said that she was pronounced dead in hospital, however they later said that she was in fact in critical condition.
The driver of the transport truck remained at the scene.