The main construction contract for the A303 Amesbury to Berwick Down scheme includes eight miles of new dual carriageway and a tunnel at least two miles long underneath the Stonehenge World Heritage Site in Wiltshire.
The main works contract also includes a new bypass to the north of the village of Winterbourne Stoke and the construction of new junctions with the A345 and A360 either side of the World Heritage Site.
Highways England has published its contract notice in the Official Journal of the European Union, marking the start of an 18-month procurement process.
The OJEU contract notice covers the £1.25bn main works contract for the construction of the tunnel’s civil, structural, mechanical, electrical and technology components, including the tunnel boring machine, along with the approach roadworks and structures and the environmental components of the scheme.
Contracts for enabling preliminary work will be procured separately, as part of the total £1.7bn capital cost of the scheme.
The project does not yet have planning consent granted but Highways England is keen to maintain momentum to enable construction to start in 2021.
Although the A303 upgrade was once envisaged as a potential second generation private finance initiative (PF2) project, the Treasury has subsequently acknowledged the flaws in the PFI model and dropped it for future projects. The A303 upgrade and Stonehenge tunnel project is now proceeding on the basis that it will be conventionally funded by the Treasure, via the Department for Transport (DfT). A Highways England spokesman said: “As far as Highways England is concerned, the A303 outline business case has been approved by government, and funding for all capital projects will be determined at this autumn’s spending review. In the meantime, the project has the funding to progress according to the plan.”
The procurement model is through competitive dialogue allowing a period of design development and dialogue during the tender phase when solutions are developed and tested for compliance with development consent order (DCO) requirements ahead of a contract being awarded.
Highways England project director Derek Parody said: “We expect this scheme to be of interest to some of the world’s best construction companies, who want to be part of delivering this transformational project – a scheme which will not only unlock congestion along this vital A303 route, conserve and enhance the Outstanding Universal Value of the World Heritage Site but also benefit the local and regional economy by providing skills and job opportunities for businesses large and small.
“This in no way pre-empts the outcome of the ongoing development consent order examination. While this continues to progress, we need to begin the procurement to put us in a position to be able to start construction on schedule in 2021, providing consent is given.
“The start of the procurement process demonstrates the government’s continued commitment to this scheme and an expectation that progress on it continues as planned."
However, political risk on this project remains high. A report by the National Audit Office (NAO) in May 2019 cast doubt on the value for money offered by it. Amyas Morse, the head of the NAO, said: “The tunnel at Stonehenge is currently only just value for money by the department’s own business case. Based on experience, project costs tend to grow rather than fall, at least in the early years. It will take a very special effort by the department to protect public value up to completion.”
The House of Commons public accounts committee (PAC) has also thrown doubt on the project. Although the Treasury has released £21.5m funding for 2019-20 to allow the project to keep going, the DfT does not expect to fund the project from its £25.3bn draft funding envelope for roads, 2020-25. Instead, it intends to make a case to the Treasury for additional funding for the project as part of the next spending review, the timing of which is still uncertain.
Deputy PAC chair Sir Geoffrey Clifton-Brown said earlier this month that government plans to open the Stonehenge tunnel by 2026 remain in doubt until a clear decision is made on funding. “To meet the proposed timetable a funding decision is needed by the end of this year,” he said. “Stonehenge is one of the world’s greatest heritage sites. There is a pressing need for the Department for Transport and Highways England to set out exactly what benefits visitors and local people near the site can expect to see as a result of the scheme.”
Contractors interested in more details of the procurement process for the A303 Amesbury to Berwick Down scheme (project reference PQQ_750) should go to Highways England’s procurement portal at www.highways.bravosolution.co.uk