The claim by ministers that the proposed high-speed rail line between London and the north could give the UK economy an annual boost of £15bn has been labelled “fanciful” by one of the government’s own transport advisers.
The estimate of how much the £42.6bn High Speed 2 scheme could help lift GDP was a key part of the defence of the project mounted by Patrick McLoughlin, transport secretary, in a wide-ranging speech on Wednesday that sought to draw a line under weeks of intense criticism of the project.
But Dan Graham, a professor of statistical modelling at Imperial College London, told the Financial Times the £15bn figure “seems to be on the optimistic side”.
Prof Graham has advised the government on both HS2 and Crossrail, the £16bn project under construction in London.
He also provided the statistical modelling that underpins the standard government way of assessing the economic business cases on both schemes.
But Prof Graham said: “These numbers really need to be scrutinised, otherwise they could turn out to be fanciful.”
His criticism was backed by others, including Richard Wellings, head of transport at the Institute of Economic Affairs.
“This lossmaking project fails the commercial test, while standard cost-benefit analysis