Drivers have been advised to avoid the A47 after a driver suffered a medical episode at the wheel.
Norfolk police tweeted at 4.30pm on Friday night to say they were on scene at the incident on the eastbound carriageway between the A140 and the A146 turnings.
They said it was 'likely to cause delays' and advised drivers to allow extra time for their journey, or find an alternative route.
Emergency services were called just before 4.20pm after the driver suffered the medical episode.
Ambulance crews are on scene. The driver's condition is not yet clear.
All lanes have reopened but traffic remains heavy.
It came just before another crash on the eastbound carriageway at a similar time, after the Harford park and ride slip road.
The incident was understood to have been a single-vehicle crash, with traffic queuing back to the Thickthorn roundabout.
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