Highways Agency bosses have said they 'regret' inconvenience caused to drivers who found themselves delayed for up to an hour because of roadworks at a roundabout near Norwich.

Motorists hit out at long delays to their journeys after roadworks at Thickthorn roundabout left them queuing for nearly an hour along a one mile stretch of the A11 on Thursday night.

The Highways Agency, which is carrying out £650,000 work at Thickthorn roundabout, admitted there had been an 'issue', caused by the temporary suspension of the system which monitors traffic – which affected the phasing of the traffic lights.

An agency spokeswoman said: 'The resurfacing scheme at the Thickthorn roundabout will improve journeys in this area for road users.

'Overnight on Thursday the work required the temporary suspension of the system which monitors traffic and sets the traffic signals. We are aware this led to some delays and regret any inconvenience caused.

'This is being addressed and we expect traffic flows to return to normal. We thank drivers for their patience.'

Work to improve the worn out surface started last week, but it was last night that drivers really felt the impact of the work.

One commuter left work in Wymondham at 8.45pm last night. He said he arrived home in Acle at 10.45pm after spending 50 minutes stuck in traffic on the A11.

Frustrated motorist James Palmer tweeted: 'Long queues A11 northbound because of Thickthorn roadworks.'

And Tom Ramsay tweeted: 'We were one short at 6-a side because one lad got stuck in it. It's outrageous it's being done in the evenings.'

Jessica H tweeted that she had also been caught up in the queues. She said that driving home to Norfolk from Surrey, she was stuck on the M25 for an hour and then spent an hour stuck at Thickthorn.

The Highways Agency started the £650,000 work last Monday to resurface the roads around the roundabout and the slip roads on and off the A11 and A47.

The Highways Agency said the work was being undertaken overnight between 8pm and 6am to 'minimise disruption' to road users.

The road markings, which are barely visible on parts of the roundabout, will also be restored.

To ensure the work can be carried out safely for road users, there is a 50mph speed restriction, and specific lanes or carriageways are closed.

The work is expected to last until March 6.