Ontario provincial police said it happened in the west lanes of the highway near Brock Road shortly after 5:30 p.m.
OPP Sgt. Kerry Schmidt said eyewitnesses told police two motorcycles were traveling at high speeds and crossing the lane when one of them stuck a vehicle before colliding with a second vehicle.
The rider, a 34-year-old man, then jumped off the motorcycle, Schmidt said.
He was airlifted to a Toronto trauma center with life-threatening injuries.
“Please drive safely, drive responsibly and follow the rules of the road,” Schmidt said. “This kind of behavior is completely unacceptable on our highways.”
The lanes west of the freeway between Brock Road and Westney Road remain closed Friday night. Schmidt said the closure is expected to be completed around 10 p.m.
