This is an interesting train of thought, pun kind of intended.
I’m confused by the maths, particularly around the number of people who can fit in a Jubilee line train, and I wonder if you’ve made some assumptions that I haven’t or vice versa? My own maths abilities are absolutely appalling so it’s entirely possible I’ve missed something very obvious.
For example, if a Jubilee line train has 7 cars long and holds 26 passengers total, this means fewer than 4 people per car. Each car is slightly in excess of 2 metres wide and so I guess it’s touch and go whether people could stand on opposite sides of the car. With a person in each corner of each car as a minimums , this gives a capacity of 28 for the train but my first assumption there is that social distancing doesn’t need to be observed through the walls between the cars, and also that people can cram themselves into the corners enough to maintain the 2m gap.
If standing on opposite sides of the car works, and each car is around 17m long, I reckon you could get 8 people on each side of the car for a total of 16 per car, or around 124 per train (without factoring in cabs).
I think the difference comes down to how we’re spacing people out. I think the figure of 12.56m^2 per person double counts the space between people, and you end up with people placed 4m apart rather than 2? If you assume each has a 1m radius around them, and you place two 1m radius circles with their circumferences touching, the distance between the two centre points is 2m. If you then divide the 327m^2 train by 3.14m^2 you get almost 34 people per train with the caveat that dividing a rectangular space into circular areas wastes some space because circles don’t tesselate well. You can’t fit people into those spaces so assuming then that the effective area per person is 4m^2, i.e. a square with sides of 2m per person, you get 327/16 people per train which is about 20. This, of course, assumes that people don’t stand against the walls of the cars.
So if you then assume that people stand directly on either side of the cars and you place 4m^2 squares between each, you effectively have a car with 4.630m width, around 82m^2 area per car, 573m^2 area per train or 35 people per train. Assuming 20tph it’s around 180 passengers per hour difference.
Out of interest I then imagined a Jubilee Line train to be more like an escalator. If you’re dealing with straight lines of people like on an escalator, the train has 17.77*7 metres of length, and dividing by 2 gives 62ish people per train.
Have I got totally lost here? I’m genuinely intrigued by the figures, certainly provided some food for thought with the insomnia!