The North Carolina Highway Patrol said the driver of a tractor with a mower attachment was working in the median with safety vehicles behind it when it happened around 11 a.m. at the Newton Grove exit.
The truck sideswiped two of the safety vehicles before hitting the mower. The mover driver - 47-year-old John Glenn McLean - was pronounced dead at the scene.
McLean's son was in one of the safety vehicles. He was taken to the hospital for observation.
The driver of the truck - 65-year-old Luis Valdes of Lehigh Acres, Florida - suffered minor injuries.
Troopers say the tractor trailer speed was between 65 and 70 mph.
"At this point it's still unclear what the circumstances was, whether it was fatigue or lack of sleep or lack of attention, but it did appear that his attention was caught after striking the second vehicle then subsequently crashed into the tractor and killed the driver," NC Highway Patrol Trooper Marcus Bethea said.
Investigators say charges are pending at this time.