I'm not sure if it's been mentioned in the thread before, but there is an underground train station under Manchester.
I don't know why it was abandoned or how far it goes. But I wonder if any of the hs2 planners knew about it.
I was watching one of the travel vloggers on YouTube and he went to Stockholm, Sweden. They have an underground very fast track.
On a slightly different tangent I'd like to see existing train stations be standardised, particularly when it comes to platform height. Because the amount of stations disabled people in chairs need a ramp for is ridiculous and embarrassing. It really shows how some folks are happy to trundle along with 1950s stations.
I think i've said it before.
But as an idea of how badly planned/thought out and how little the rail network thinks of disabled people when they redid our local station in a "multi million pound refit" to much publicity back in the late 90's they didn't bother to replace the ancient foot bridge as "not enough disabled people use the station to justify a new foot bridge with lift".
So for another 10-15 years they continued to have anyone in a wheelchair having to be pushed across the tracks, which IIRC meant either turning up and waiting for a station attendant to be free and able to confirm that it was safe for them to accompany you over the track (meaning trains had to slow down/be put on warning/hold), or you had to ring up in advance, both of which meant you couldn't use a train on the spur of the moment or without considerable planning to allow for when they could do that.
It was no wonder disabled people didn't use the station, it wasn't suitable for anyone with any mobility problems (even "just" a bad knee or ankle) and barely safe for people with poor eyesight as the old bridge was (and still is) pretty bad IIRC higher than standard steps, and risky when wet. At the time the decision was made to not put the disabled access in there were petitions from the local disabled people/groups explaining that the primary reason they didn't use it more was because it was unusable for them.
A large part of the problem with "standardising" the stations is something that actually ties into the reason we need a lot more rail tracks laid, at the moment any work on any station is massively disruptive and can take years to do what should be a few months work, because every time you work on the track or the station you need to at the very least slow down all trains using that route even if they're not on the line you're working on, and there are almost no places where you can route around works.
IIRC it took something like 5 years of work for them to put new overhead footbridges with lifts in at Watford Junction (or was it Clapham?), including something like a year to get the lifts installed after they'd got the rest of it usable, mainly because they could only work for a few hours overnight and close the tracks over which they were working for maybe a day or two at a time on bank holidays.
It also doesn't help that they've basically sold off much of the "extra" land that used to be around train stations and directly adjacent to them, so they can't expand the stations that need it even just lengthways along the side of the track in many place.