Update 4.30pm: The road has now fully reopened.
A five-mile stretch of the A15 will be closed until at least 5pm after a lorry jackknifed this morning.
As reported previously, the lorry overturned close to the Caenby Corner roundabout, with the road closed north of there up to the B1205.
Delays have been reported on the B1205 as motorists follow alternative routes.
Avoid the area if at all possible.