The A16 Spalding Road in Boston has now re-opened after a serious collision involving a pedestrian and a car.
The incident happened at about 1.40pm this afternoon near the pedestrian crossing close to the Black Sluice Cafe with the female casualty taken to Pilgrim Hospital for treatment.
The victim is aged 24. She is said to have suffered a series of fractures and a brain injury although her condition is not yet clear.
The road was shut between Liquorpond roundabout and the ATS roundabout for about three hours, re-opening at about 4.45pm.
The closure brought traffic to a complete standstill across the town, with motorists reporting long queues during the school run.
A force spokesman called for patience while a forensic examination was carried out at the scene.