Engineers from Highways England have been manning the Thickthorn roundabout to watch for further problems since commuters were caught in queues on the A11 this week.

Delays of more than 30 minutes were experienced as traffic became clogged between the roundabout and Wymondham on Tuesday and Wednesday mornings.

Similar issues were found during the summer between July 25 and August 3, but Highways England insist the problems were unrelated.

The delays during the summer were attributed to the resurfacing of the road network, while faulty detectors were the root of this week's problems.

'We're sorry for the disruption on the A11 at Thickthorn on Tuesday and yesterday morning and would like to reassure road users that we are working hard to find a solution to the problem,' said a spokesman for Highways England.

'We became aware of a traffic light issue on Thickthorn roundabout on Tuesday morning and sent an engineer out to investigate.

'The engineer who attended site on Tuesday found a fault with the traffic flow sensors which feed data to the traffic lights system at the roundabout and carried out a repair.

'As a precaution the engineer attended site again yesterday morning during travel peak time to ensure the installation was operating correctly. A separate fault was identified associated with detectors and a temporary repair was carried out.

'A traffic signal expert remained at the roundabout during yesterday's evening peak to monitor that the system is now operating correctly and to deal with any further issues if they arise.'

Norfolk County Council and Highways England will be meeting next week to agree what more could be done in future to further minimise disruption in the event of an unplanned fault.