A crash on the A1 southbound near Stamford is causing around five miles of tailbacks.
The accident between two vehicles was first reported at around 8.20am on Wednesday morning but it is still causing major problems and long delays.
One lane is now closed between the A6121 and the A43 near Stamford.
Lincolnshire Police is on the scene dealing with the collision but it’s unclear when traffic will get moving again or whether anybody was injured.
Highways England has warned motorists to allow for extra time for their journey.