Welcome brake on a runaway train Today, we report that Treasury approval for HS2, the new high-speed rail link between London and Birmingham, has been held up - despite George Osborne, the Chancellor, voicing great enthusiasm for the project. Unsurprisingly, HS2 Ltd, the company that will be responsible for building the line, is upset that permission to start hiring contractors for this £33 billion project has been delayed. Minutes from its company meetings reveal that this could put "whole project timelines in jeopardy." We do not share the firm's disappointed reaction. On the contrary, we are delighted that the Treasury's careful scrutiny is being applied to the cost/benefit analysis that has been used to justify building the rail link and to "prove" that it will represent value for money. Building the link will reduce journey times between London and Birmingham by almost 40 minutes. That much is agreed by the project's proponents and critics alike. What is less certain is that it will eventually generate billions of pounds, as has been claimed by its supporters. But we do know that official analysis of the proposed new line has twice reduced its estimate of the economic benefits. The case for the high-speed line needs to be made with complete clarity. In addition to costing a fortune, it will destroy some of Britain's most beautiful countryside. Major infrastructure projects undertaken in Britain do not have a high success rate. No one wants HS2 to end up like "Connecting for Health," Labour's project to revamp IT within the NHS. That was abandoned unfinished, but not before £12 billion of public money had been wasted on it. The even greater costs of HS2 make it all the more vital that ministers do not allow over-optimism to get the better of good judgment.