Stephen Boone Roberts may have fallen asleep around 1 a.m. when his Jeep left Ga. 400 and overturned, killing the 32-year-old Dahlonega man, authorities said.

Roberts was driving his 2004 Jeep Wrangler north on Ga. 400 when his vehicle left the roadway about a half-mile south of the Ga. 306 exit, according to Investigator Ron Tomblin, traffic specialist with the Forsyth County Sheriff’s Office.

The Jeep hit a guardrail, rolled several times, and then struck a tree, Tomblin said. Roberts was thrown from his vehicle and was dead at the scene. An investigation is continuing to determine why Roberts’ vehicle may have left the road.

He was alone in his vehicle and was not wearing his seat belt.