THE estimated cost of dualling the final single carriageway stretch of the A11 has risen from �30m to �147m in nine years, according to figures released today.

THE estimated cost of dualling the final single carriageway stretch of the A11 has risen from �30m to �147m in nine years, according to figures released today.

The increase in cost represents a staggering rise of 390pc and comes as the Campaign for Better Transport (CBT) accuses the Highways Agency's road-building programme as being “significantly over budget”.

Citing the Highways Agency's own road budget figures released through a Freedom of Information request, the CBT says that many road projects in the East of England are running up to 420pc over their original budget.

They say the A11 scheme to dual the stretch between Fiveways and Thetford was initially supposed to cost �30m in 2000 but is now expected to cost up to �147m.

Stephen Joseph, executive director of the CBT, said: “It is fair to say that inflation has not been 390pc in that period.”

He added that the figures were illustrative of a “system of under estimation of costs” which he said had been criticised by various bodies.

In March 2000 it was reported the cost of dualling the stretch of road to be an estimated �30m. By July 2006 this had risen to an estimated �101m and by May this year the figure had increased to �135m with work due to start in 2010.

But the Highways Agency has hit back at the CBT's claims and a spokesman said that while he could not go into specific details about individual road programmes this was an issue over cost estimating and not overspending.

The spokesman said: “To say our road building programme is significantly over budget is wrong. There have been no significant changes in outturn costs on schemes open to traffic or schemes in construction since the latest costs were published in July 2008.

“The government announced in January a programme of up to �6 billion investment up to 2015 to improve the national road network. We are progressing the schemes in this programme as per the timetable in the January announcement.

“We have recently strengthened our ability to deliver our major road schemes to time and budget by making significant improvements to the way we estimate the cost of planned road schemes to deliver more accurate estimates.

“We now provide cost range estimates rather than single point estimates, and these are regularly reviewed as a scheme is progressed through various phases.”

The spokesman said the increase in costs between programme entry and completion was examined fully in a report published in March 2007. Amongst its key findings was that one of the biggest increases in construction costs was due to inflation in construction costs being higher than general inflation across the economy.

The report led to a review of the Highways Agency's major roads programme which recommended that schemes progress through a project lifecycle with investment decisions being made at key stages.