The independent review of High Speed 2 is unlikely to change minds

During the campaign for the Conservative Party leadership, Boris Johnson promised to launch an independent review of High Speed 2 – a new high-speed rail line which would connect London and Birmingham and extend separately to Manchester and Leeds. Now, as prime minister, Johnson has announced its terms of reference.

Although the legislation enabling the government to build the London to Birmingham section of the line was passed in February 2017, and the government has already spent over £4bn on the project, shovels have yet to hit the ground. Even at this late stage the project could still be cancelled – transport secretary Grant Shapps has promised a “go or no go” decision following the review’s conclusion.

The review is asking the right questions

An independent review is a sensible way to consider the case for HS2. While the decision is ultimately one for ministers, it is better that this is informed by evidence, rather than narrow electoral interests: several cabinet ministers, including the prime minister, represent constituencies on the proposed route. The review panel – made up of both HS2 sceptics (such as Labour peer Lord Berkley and academic Tony Travers) and HS2 supporters (including Douglas Oakervee, the former chair of HS2 Ltd, and West Midlands mayor Andy Street) – suggest that it is a genuine attempt to review the costs and benefits of the project.

The terms of reference for the review are wide-ranging. Reviewers have been asked to consider all costs and benefits, such as how HS2 could impact services not on the new line and impact the economy. This is encouraging, as it should allow the government to make an informed decision about whether the project would still be beneficial even if, for example, the costs rise significantly – as has happened with many other major projects.

The government has explicitly asked reviewers to consider “whether there are alternative strategic transport schemes which could achieve comparable benefits in similar timescales”. This should be welcomed. Many big projects often commence without having a clearly-defined problem to address. This means that governments do not consider alternative options, which could be more efficient or effective, to achieve their objectives. The review's terms of rerefence should help the government respond to concerns that it has not considered whether other options – such as improving regional rail links in the North – would be better alternatives, as the Lords Economic Affairs committee argued earlier this year.

The short timescale risks undermining the findings

But the review – which has been asked to report by Autumn 2019 – has not been given much time to consider these big questions. By contrast, the Airports Commission – a review into airport capacity in the South East – took two-and-a-half years between launching in 2012 and publishing its final report in July 2015.

It is also unlikely that the reviewers’ minds will change over such a short time-frame – and a review which concludes without agreement will fail to settle the issue. Institute for Government research has shown that reviews are most effective when all reviewers agree, but can be undermined when there is dissent, such as with the Royal Commission on social care.

HS2 doesn’t stand alone as a major infrastructure project

This is not the only review of major infrastructure projects this Autumn; the government is also due to publish its first National Infrastructure Strategy later this year. It would be better if the government decided whether, and how, to progress HS2 on the basis of its contribution to overall objectives for infrastructure investment.

However, the Conservative Party leadership campaign highlighed the extent to which HS2 has become a contentious issue and prompted Johnson's promise to review. As such, it will now be considered in isolation. But a standalone review, especially one conducted on such a compressed time scale, is unlikely to changes minds or shift the debate in any meaningful way.