Britain is building the most expensive railway in the world. Many people now think it’s pointless | CNN

The HS2 high-speed rail line was supposed to re-energize the UK. Instead, controversy, astronomical costs and downsizing have left it struggling for support.

Source: Britain is building the most expensive railway in the world. Many people now think it’s pointless | CNN

fta:

With its first — and now only — phase currently costed at between $58.4 billion and $70 billion by the UK government, Britain’s High Speed 2 (HS2) rail project now costs an eye watering $416 million per mile.

For comparison, the Tours-Bordeaux TGV line in France cost around $32-$40 million per mile in the mid-2010s — although much of that line runs through sparsely populated agricultural regions.
…
European high speed rail projects outside the UK typically cost around $66.4 million per mile

this gives some broad estimates for the cost of ontario’s proposed hs rail from widnsor to montreal.