This is the long-anticipated sight of work which has now begun to dual the last remaining single stretch of the A11.

Preliminary work on the dualling between Thetford and Barton Mills began on October 17 on an access road at the Elveden Estate, used for heavy farm vehicles.

Upgrading this has been accelerated by a year to ensure main construction work to widen the last nine-mile stretch of the A11 starts on schedule in 2012/2013.

The work will allow the Elveden Estate easier access to the A11 and enable it to cope with an anticipated increase in journeys.

Trees have been felled to widen the track, which will be used by farm vehicles, and this week work has begun to lay a base on which the asphalt track would sit.

A spokesman for the Highways Agency said between 10 and 15 workmen were on the site at any one time.

It is believed the preliminary works will be completed in March 2012.

While the work is not construction of the A11 proper, it is believed that by beginning preparatory works early, the scheme as a whole will be completed on time in 2014/2015.

Announcing the beginning of the project at the Elveden track last month, roads minister Mike Penning said bringing the start date forward by a year would allow the Highways Agency a 'fallback position', should the work be affected by bad weather.

The scheme to upgrade the A11 to dual-carriageway standard between the Fiveways Roundabout at Barton Mills near Mildenhall and the southern roundabout of the Thetford bypass will comprise 5.5 miles of widening as well as a 3.6 mile bypass of the village of Elveden.

Before main construction work gets underway, advanced environmental works will be carried out. Dates will be confirmed by the Highways Agency nearer the time.

Currently, Norwich is the largest city in the UK not linked to the rest of the country by dual carriageway.

Prime minister David Cameron confirmed earlier this year that the �134m scheme would begin in the next financial year which was welcomed by campaigners who had fought for decades for the road's completion.

The dualling is a key improvement to transport links and research by the then East of England Development Agency two years ago showed the scheme would save �690m in lost time when completed.

rebecca.gough@archant.co.uk