Emergency services were called to a crash outside Coombe Farm, which police described as being between Foxes Cross and Great Torrington.
Police said they believed only one vehicle, a Land Rover, was involved.
The driver was pronounced dead at the scene.
The road was blocked and police set up diversions after the incident at 4pm on Friday.
Police are looking to speak with the driver of a small blue vehicle that was travelling on the unclassified road between Torrington and Alverdiscott between 3.30pm and 4pm on the day of the incident.
Anyone with any information is asked to contact police on 08452 777444 quoting police ref 594 050210.