A 54-year-old woman died at the scene near Crianlarich, police have confirmed.
The line between Crianlarich and Fort William was closed from October 5-14, to allow vital engineering works to take place.
Works start Monday September 2 for four nights.
Police are keen to speak to anyone who may have dashcam footage of the incident.
Motorcyclist was caught in speed trap on A85 in Glen Dochart.