Police are appealing for witnesses after a black Landrover Discovery left the road on the A16 at Surfleet and collided with a roundabout.
The incident happened at approx 5.45pm yesterday (Monday).
A 69-year-old local man, who was driving the vehicle, was taken to Boston Pilgrim Hospital and later pronounced dead.
Any witnesses who have not already spoken to officers at the scene are asked to call 101, quoting incident number 310 of January 16.
The road was reopened shortly after midnight.