An 82-year-old man is dead following a motorcycle crash on Highway 401 near Courtice, Ont. on Thursday afternoon.

Emergency crews were called to the on-ramp from westbound Highway 401 to northbound Highway 418 shortly before 4 p.m. for a single-vehicle collision.

Police said a motorcycle, for unknown reasons, left the roadway and crashed into a ditch.

The rider, who was from Mississauga, suffered life-threatening injuries and was taken to the hospital, where he was pronounced dead, police said.

The cause of the crash is unknown. The ramp was closed for several hours but has since reopened.