Tunnel Under Stonehenge Part of £15 Billion UK Road Building Plan

A general view of Stonehenge during the annual Perseid meteor shower in the night sky in Salisbury Plain, southern England August 13, 2013. Kieran Dohert/Reuters

The UK government announced plans today to tunnel under the iconic prehistoric landmark Stonehenge as part of a multi-billion pound initiative to expand Britain's roads and boost the economy.

The proposed tunnel under the stone circle, an UNESCO World Heritage Site, will be 1.8 miles in length and is estimated to create 1,300 jobs. The Department for Transport said that details on the tunnel's design and depth are as yet unconfirmed, with construction expected to begin between 2019 and 2021.

Dubbed a "super highway", the tunnel is meant to be an alternative to the M4 by connecting London and Devon, adding an extra lane to parts of the A303 that remain single carriage.

The £15 billion road investment strategy, announced in advance of the government's autumn budget statement, will allot £2 billion to the roadway under Stonehenge. The plan also involves the construction of 80 new roads and the improvement of existing junctions across the country. The changes intend to ease traffic congestion as the RAC predicts seven million rise in the number of drivers in the UK over the next 20 years.

Transport secretary Patrick McLoughlin was enthusiastic about the initiative, saying: "Today I'm setting out the biggest, boldest and most far-reaching roads programme for decades. It will dramatically improve the network and unlock Britain's economic potential." The funds were initially announced in 2013 but not publicly allocated until today's announcement.

The opposition Labour party pointed out that no additional money had been announced, with shadow transport secretary Michael Dugher calling the government's record on infrastructure spending "all talk and no delivery".

The plan received a cautious welcome from the National Trust and English Heritage, who regarded the Stonehenge tunnel as an improvement.

In a joint statement, they said: "The existing A303 is highly detrimental… we will continue to work with the Department for Transport to identify a solution that both improves the world heritage site and is achievable, including a tunnel option."

Other major roads such as the M25, A23, A27, and A34 will be upgraded as part of the strategy. This includes the expansion of the M25, that circles London, into a 4-lane highway by the end of the year.

Several of the planned expansions, including development the A57 through the Peak District, mean building on National Park land, leading to concerns that the government is backtracking on environmental commitments. The Campaign for National Parks (CNP) condemned the government proposal, saying the announcement brought "little comfort to National Parks". The non-profit organization regards the road proposals as a threat to protected landscapes, saying: "The announcement of the road schemes – covering the Peak District, South Downs and Broads Authority National Parks - is completely contrary to the government's own policy on road building in National Parks and fails to take account of the importance that the public attach to protecting parts of the countryside from development."

Although the CNP welcomed the £300 million in funding for environmental improvements that came with the road announcement, they are still far from the £3 billion target campaigners want in the next five years.

Ruth Bradshaw, policy and research manager at the CNP, said that "there is a strong presumption against any significant road widening or the building of new roads through a Park, unless it can be shown there are compelling reasons for new or enhanced capacity and with any benefits outweighing the costs very significantly." Investments in connective "trunk" roads should be spent on developing routes for long distance traffic that avoid the Parks, she said.

Bradshaw continued: "90 million people visit National Parks every year, eager to experience their unique qualities but too often their enjoyment is spoilt by traffic noise and unsightly, dangerous roads. Today's announcement provides far too little to reduce the impacts of existing roads on National Parks."

The plans were announced ahead of the autumn statement due on Wednesday. Chancellor George Osborne also announced an extra £2 billion per year to the NHS, describing the funding as "a downpayment on the NHS' five-year plan".