The consortium of investors certainly sees it as viable, to the extent that there’s no reliance on public subsidy for the project. Switzerland has the advantag

The consortium of investors certainly sees it as viable, to the extent that there’s no reliance on public subsidy for the project. Switzerland has the advantage of being relatively compact, so I do wonder how the economic case would stack up with different geographies. High capex, low opex. Lower capex with above-ground tubes as you suggest. I think Futurama was onto something.