A man, 78, has died after a two-vehicle crash on the A17 near the Sutterton roundabout.
Emergency services were called at 4.30pm on Sunday to the collision involving a silver Vauxhall Meriva and a beige Vauxhall Zafira.
The driver of the Meriva, a man from Hemsworth. was taken to Pilgrim Hospital, Boston where he died.
A 21-year-old old man from Spalding who was driving the Zafira was not reported injured and was arrested on suspicion of causing death by dangerous driving.
The road was closed until about 10pm as investigations were carried out and the vehicles recovered.
Police are asking for anyone who was in the area about the time of the collision and either saw the collision itself or either the silver Vauxhall Meriva or the beige Zafira prior to the collision to contact them on the non-emergency number, 101.