Drivers are being advised to avoid the B1105 between Fakenham and Wells.
The road was blocked near the North Barsham junction, according to Norfolk Police.
The blockage was reportedly a tractor and trailer that rolled over.
Police were at the scene.
Queues were building, with traffic moving slowly around the junction.
The road is now clear, according to police.
For up-to-date information about the county's roads, visit our LIVE Norfolk traffic map.
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