Council officials have vowed to keep up the pressure for improvements to the A47 in West Norfolk, though any work could still be up to 20 years away.
The borough missed out on a share of a £300 million package of government funding for the road, which was announced by ministers in November.
And a new report has suggested that campaigners’ dream of a full dual carriageway could cost more than £400 million to complete in our area alone.
But officers are urging councillors to continue the campaign for extra cash when the issue is debated at a meeting later this week.
Following the government’s pledge to invest in the A47, five sites in Norfolk have been included in the Highways Agency’s programme of works for the period up to 2021.
Although officials have described that as a “good start”, a report to the county council’s environment, development and transport committee, which meets in Norwich this Friday, says the long-term aim of a full dual carriageway should remain the target.
Among the areas of concern are the Pullover, Saddlebow and Hardwick roundabouts in Lynn, together with a new A10 link road, which is proposed to join the A47 east of the Hardwick junction, as part of plans to build 1600 new homes in the West Winch and North Runcton areas.
Those plans form part of West Norfolk Council’s blueprint for future housing development in the area for the period up to 2026. A public consultation on that project began yesterday.
But, while work to identify the exact measures needed is still continuing, the report warns that any work in the area is likely to be many years away.
It said: “All options would require dualling the A47 between the link road and Hardwick Junction by 2026 and possibly dualling the Hardwick Flyover by 2035.”
A study of the Hardwick junction is ongoing, while the document says the council will need to consider whether further studies need to take place at the Saddlebow and Pullover roundabouts.
Elsewhere, three single carriageway stretches from Tilney to Lynn, Lynn to Swaffham and Swaffham to Dereham are among the sites identified as needing a government investment commitment for improvements.
However, the report suggests that dualling the Tilney to Lynn stretch would cost around £36 million, with another £68 million needed to upgrade the Wisbech bypass.
The report said work to develop the case for dualling should continue in order to increase the chances of investment in the spending window after 2021.
Meanwhile, it is thought that as much as £320 million would be needed to dual the Lynn to Swaffham and Swaffham to Dereham stretches.
And, while the frustrations caused by slow-moving farm vehicles and drivers turning at junctions were acknowledged, the report said: “Analysis undertaken for the county council predicted that both would not be operating over theoretical capacity until the mid-2030s.”
However, the report insists that all the schemes represent good value for public money and could generate anywhere from 1.67 to 2.82 times their cost in economic benefits to the area.