Part of the NDR was blocked after a car overturned in a crash.
Traffic was queueing on the southbound carriageway at the junction with the A47 in Postwick from around 4.30pm on Thursday, February 6.
Crews from all three emergency services were on the scene.
Three fire crews from Wroxham, Gorleston and Loddon were called to the crash at 5.30pm, where they extracted one person from a car using hydraulic rescue equipment.
Diverting traffic was expected to cause heavy delays on roads in the area.
The Konect 5a, First 15/15A, First X1/X11 and Park and Ride 5/500 bus services could have all be affected.
A car was spotted on its side, with one passer-by saying that the windows were smashed in and with people possibly inside.
Sam Tetley-Berry said: "Just seen all the flashing lights. Luckily I was at the previous roundabout so I could go right and head to the A47 the old way.
"Hope all involved are okay."
The AA's traffic map reported at the time that there was congestion on the northbound carriageway "as people slow down to look at the accident".
Claire Frost said: "We joined the A47 at Trowse and couldn't even get off the slip road all because of nosey people stopping to have a look on the other side."
Norfolk Fire said crews left the scene just after 6pm.
Traffic is now flowing normally in the area.
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