Engineers’ question ‘flawed’ HS2 claims

Chris Richards, Transport Policy Advisor at the Institution of Engineering and Technology, said: “In our response to the Department for Transport consultation we made it clear that there were potential flaws in the analysis, several assumptions were made in crucial areas and serious questions have been left unanswered.”

Today the National Audit Officeexpressed "reservations about the business case" for the high-speed train line.

HS2 between London and the West Midlands is due to open in 2026 and the full Y-shaped network, with lines from Birmingham to Manchester and Leeds, is due to open in 2032.

The NAOsaid the Y-network has a stronger economic case but is much less certain as route designs are less well-developed.

"In presenting its case for investment in the project, the Department of Transport has poorly articulated the strategic need for a transformation in rail capacity and how High Speed 2 will help generate regional economic growth," the report said.

“The methodology for appraising the project puts a high emphasis on journey-time savings, from faster and more reliable journeys, but the relationship between these savings and the strategic reasons for doing the project, such as rebalancing regional economies, is unclear."

Mr Richards said the original High Speed 1 business case was based on journey time saving benefits and increased rail capacity.

“The total value of these benefits is not known as the Department for Transport has not yet developed a method to evaluate HS1 project costs against benefits, despite this forming part of the High Speed 2 justification,” he said.

“High Speed 2 is a project of major national significance, if we get this wrong, we will regret it for decades to come.”

The NAOreport said the estimated cost of phase one will change as costs become firmer.

In some documents, the estimated cost is between £15.4bn and £17.3bn, but a new estimate is being developed based on a clearer route and more information. The NAOestimates that there is a £3.3bn funding gap over four years (2017-18 to 2020-21) which the government has yet to decide how to fill.

The NAOsaid the benefit-cost ratio calculated for phase one has twice contained errors and the Department has been slow to carry out its own assurance of the underlying analysis.