Delayed A12 reconstruction work is £10m over budget

National Highways has been reconstructing the A12 between junction 13 at Ingatestone and junction 15 at Three Mile Hill

A major reconstruction scheme on the A12 is running £10m over budget, a Freedom of Information (FOI) request has revealed.

National Highways estimated it would have cost £75m by the time it finished work on the Margaretting bypass in Essex.

The FOI, submitted by the BBC, also showed the project was due to be completed 75 days late on 7 September.

Karl Brooks, of National Highways, said "difficult ground conditions" had contributed to delays.

The scheme started on 27 February 2023 and was initially estimated to conclude on 24 June this year, having cost £65m.

Workers have been reconstructing 1.9 miles (3km) of the A12 between junction 13 at Ingatestone and junction 15 at Three Mile Hill.

The roads authority said the project would allow motorists a "smoother, quieter journey" when complete

There are six lanes between the junctions, with 11.4 miles (18.3km) of concrete road being improved in total.

National Highways said four of the six lanes had been reconstructed as of May - a total length of about 7.6 miles (12.2km).

A contraflow system has been in place throughout the project, which is expected to extend the road's life by up to 50 years.

Mr Brooks, National Highways' programme delivery manager, said "difficult ground conditions" meant the site required more extensive treatment and deeper excavation.

He added that a water main also had to be diverted and asbestos removed, which increased costs.

“We have had the wettest March on record and faced similar difficulties with weather earlier in the year," he said.

"We want these roads to last four decades, so making sure the foundations are sound is paramount to their longevity."