Utah Highway Patrol reports a Ford Explorer was traveling near mile marker 339 when two drivers saw the vehicle veer to the right.
The driver over corrected his vehicle to the left and rolled the vehicle 4 to 5 times, according to the UHP news release.
The driver was wearing his seat belt but died at the scene.
Sgt. Brad Horne of the Utah Highway Patrol says fatigue is a possible factor in the crash.
No other vehicles were involved.
Four other secondary crashes under 20-miles-per-hour were caused by drivers who were looking at the wreckage on the side of I-15.