This should not have happened if the rider was looking down the road. He didn't hit the brakes until he was 40 feet away.
"A witness to the crash said as Johnson approached the semi, Johnson did not realize the rig was stopped and attempted to avoid a crash by braking. Approximately 40 feet of tire marks were visible on the roadway leading directly up the ramp on the back of the truck."
Motorcyclist airlifted following crash
Homosassa man launched off bike, strikes back windshield of flatbed truck
http://www.chronicleonline.com/content/motorcyclist-airlifted-following-crash
"A witness to the crash said as Johnson approached the semi, Johnson did not realize the rig was stopped and attempted to avoid a crash by braking. Approximately 40 feet of tire marks were visible on the roadway leading directly up the ramp on the back of the truck."
Motorcyclist airlifted following crash
Homosassa man launched off bike, strikes back windshield of flatbed truck
http://www.chronicleonline.com/content/motorcyclist-airlifted-following-crash