Mark Wild has put both cancelling HS2 and finishing its remaining core works at about £60 billion, making full abandonment little cheaper than pressing on.
That calculation sharpens the case for extending the line beyond Birmingham, because the current plan leaves a delayed west London-Birmingham route due only in the late 2030s.
110 mph HS2 trains joining the congested West Coast Main Line would run slower than 125 mph tilting Pendolinos, while the key link is not expected until 2040-2043.
Birmingham-to-Manchester Airport is now seen as the highest-benefit next step, with lower land costs and fewer expensive tunneling demands than the southern sections.
The argument marks a reversal for a project once sold as rebalancing the UK through links to Leeds and Manchester, before both northern legs were scrapped.
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Could repurposing HS2's remnants for a northern network paradoxically be the project's greatest success?
With HS2 trains set to run slower than 1970s models, is Britain's high-speed dream officially dead?