The A11 was closed northbound following a crash near Attleborough.
The road was shut between the B1077 and B1172 junctions after the accident at 8am until it reopened at about 11am.
National Highways England had told motorists to allow extra time for your journeys.
Emergency services attended the scene and members of the public reported that traffic was at a standstill.
Norfolk Police have been approached for more information on casualties.
For up-to-date information about the county's roads, visit our LIVE Norfolk traffic map.
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