I've seen visualisations similar to this before, but this one is by far the most beautiful and I could watch it all day.
I echo the sentiments on the TfL API, I've built the same Tube Tracker app over and over for more than 10 years[1] as my go-to for learning new tools[2] or testing changes to frameworks[3] and I'm not sure it's ever improved. A chap called Chris Applegate wrote extensively about his battles more than a decade ago[4], did they ever add the stations between Latimer Road and Goldhawk Road on the Hammersmith & City/Circle line?
its incredible the sentiment on TfL API without realising your country even has an API for your public transport. Thats a huge leap in itself, let alone an actively maintained one