Rush-hour drivers are facing long delays after a drain cover came off on the A47.
The cover came off in the middle of the road halfway between Easton and the Honingham roundabout.
Police are letting drivers through in turns, but the road is blocked and there are long delays in both directions.
A spokesperson said highways teams had been called, and were on their way.
Drivers have been warned they could expect delays of more than 90 minutes.
But one person said it took them three hours to travel from Dereham to Poringland.
Bus companies including Konectbus and First have tweeted to warn of delays to their services.
There are further delays on the A47 at Scarning after a three-vehicle crash blocked the road.
The incident happened at about 8.50am this morning.
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