Community leaders have pledged to lobby for improvements to congestion-hit parts of the A11.

Queuing cars is a well-known issue at the five junctions on the busy trunk road at Thetford.

An important link in the technology corridor between Cambridgeshire and Norfolk, the road is also an attraction for firms to come into the town.

In a report by Richard Doleman, chairman of Norfolk County Council’s planning and projects sub-group, to the Greater Thetford Development Partnership (GTDP), said “improvement measures” to the A11 will be provided as part of the Thetford Sustainable Urban Extension (SUE).

The 5,000 homes development planned for northern outskirts of the town and would be close to the A11 junction with the A1075.

However, the report said the works will be developer lead and “will only mitigate the direct effects of growth and not address existing problems”.

Mr Doleman asked during a meeting on Friday, February 16 if the board could write to the Department of Transport (DfT) and Highways England.

He said if the group lobbies, it will raise awareness of the issues with and “keep pressure” on those responsible to support growth and the strategic importance of the route.

The board agreed to write the letters and to also invite members from both the DfT and Highways to see the issues in person.

In the county council’s Norfolk Infrastructure Delivery Plan 2017-2027, the A11 Thetford bypass junctions are recognised as key infrastructure needed to deliver economic growth in the county.

The report states that even without the proposed houses, the junctions are forecast to operate “over their theoretical capacity by 2026”.

The report suggests a comprehensive trunk road improvement scheme would be preferable and could include traffic signals on the roundabouts.

In December Highways England published an initial report where the A11 was mooted as an expressway. A new classification of road, between a motorway and a traditional dual carriageway, traffic would flow faster than at present.

No slow-moving agricultural machines allowed to use them and junctions would be improved to allow traffic to join and leave the road at the speed of prevailing traffic.