The single-vehicle collision occurred just before 2 a.m., said Kerry Schmidt, a spokesman with the Ontario Provincial Police.
He said the vehicle, a black BMW, rammed into a piece of construction equipment before tumbling off the ramp.
The lone occupant of the vehicle, a 28-year-old man, was trapped inside the car for more than 30 minutes before emergency crews were able to free him.
Paramedics rushed the man to Sunnybrook hospital, where he was pronounced dead.
A probe into the incident is "ongoing," Schmidt said. Investigators are looking for people who may have seen the crash or believe they spotted the car in the hour before the collision.
Witnesses are asked to call the OPP’s Toronto detachment at 416-235-4981.