The A16 at Gosberton was closed for more than two hours this morning, following a collision between a Vauxhall Vectra and a tractor.
A 25-year-old man from Kirton, who was driving the Vauxhall, suffered serious injuries to his head and chest in the incident, which happened shortly after 5am.
He was taken to Pilgrim Hospital for treatment. The injuries are not thought to be life-threatening.
The road was closed until 7.20am.
Anyone who witnessed the collision contact the Collision Witness Hotline on 01522 558855, quoting incident number 36 of January 8