State Troopers were dispatched shortly after 5:00 a.m. to a stretch of I-40 westbound at the 129 mile marker near Dave Ward Drive.
A caller reported what appeared to be a drunk driver in the area, followed by a call of a wrecked black Nissan pick-up truck.
Special Agents of the Arkansas State Police Criminal Investigation Division believe someone pulled-up along 31-year old Jose Martinez's truck and shot him.
They are continuing their investigation.
Martinez's body has been transported to the State Crime Laboratory.
Anyone with information about what they saw on the highway or if they know anything about the homicide can call (501) 618-8100.