The A17 at Sutterton has been closed by police following a very serious crash between a motorbike and car.
The crash happened near to the junction with the B1397 at 5.45am on the morning of Monday, November 13.
A Lincolnshire Police spokesperson has said that the road is likely to remain closed for some time.
Motorists are asked to avoid the area and follow the diversions.
Significant delays are being reported on nearby routes, including the A17 towards Swineshead and also the A16.
Any witnesses who have not spoken to officers at the scene should call 101, quoting incident number 36 of November 13.