Drivers heading into the city from the eastern GTA saw slowdowns because of a closure of the WB 401 Tuesday morning.
One woman died after a crash on the highway in Bowmanville just after 4:30 a.m. Tuesday.
Police say a Cavalier and a tractor trailer collided which sent the car into a cement barrier, rolling onto the roof and tossing the female driver from the vehicle.
She was pronounced dead at the scene. There were no other injuries.
It's not known if the victim was wearing a seatbelt or not.
The crash has closed the WB 401 between Waverley Rd. and Liberty St. for several hours.