The A1 in both directions A52 (Barrowby) and A607 (Harlaxton) due to a collision with a heavy goods vehicle.
The HGV overturned and went over the central reservation barrier.
Emergency services including Lincolnshire Police and Lincolnshire Fire and Rescue are currently at the scene.
Road users travelling northbound are advised to follow the solid black square diversion symbol on road signs and follow the below diversion:
Exit the A1 at B117 Little Ponton and follow the B1174 into Grantham to the junction with the A52.
Turn right onto the A52 and continue on the the A52 until the A52/A15 roundabout.
At the A52/A15 roundabout take the 1st exit onto the A15 northbound.
Follow the A15 until the A15/A17 Holdingham roundabout and take the 1st exit onto the A17 westbound.
Continue on the A17 until the A17/A1/A46 roundabout and take the 2nd exit onto the A46.
Follow the A46 to the A46/A1 Brownhills roundabout and take the 3rd exit onto the A1 northbound entry slip road and rejoin the A1 northbound.
Road users travelling southbound are advised to follow the hollow black square diversion on road signs and follow the below diversion:
Exit the A1 at A52 Barrowby junction and turn left onto the A52 west.
Continue along the A52 to the A52/A46 Saxondale roundabout and take the 1st exit onto the A46 south.
Follow the A46 south to the A46/A606 interchange and join the A606 heading south east.
Continue on the A606 to Melton Mowbray and at the A606/A607/A6006 junction turn left onto A607 Norman Way.
Continue on the A607 to the A607/A606/B676 Norman Way/Thorpe Lane junction and turn left and continue on the A607.
Follow the A607 to the A607/A1 southbound entry slip road at Harlaxton and rejoin the A1 southbound.