What good is sitting alone in your train (as Liza Minnelli once almost sang)? Come, feel the people sway. Life is a grand commute, old chum — just don’t forget to spray.

Deodorant, in fact, is but the cheapest of the accessories likely to become de rigueur for passengers in the brave new world of “extra capacity” commuting being pioneered on selected southern rail routes. Other soon-to-be-essential travel items may include hammocks, stepladders and tape measures, and the last of these is key.

South West Trains, in an effort to meet government targets on reducing overcrowding, has promised extra capacity. But in most cases this will be achieved by removing seats rather than adding them. In their place, commuters will be given a fighting, or at least an elbowing, chance of being able to stake out 0.54 square metres of standing room each.

This is what the Department for Transport considers adequate, and it is, indeed, just enough to swing a compact Times. It is also extraordinarily wasteful. Armed with their tape measures and with the square root of 0.54, which is 0.73 — or with 73cm sticks that could also be used for prodding — passengers should be encouraged to use every last skerrick of unexploited air. Team leaders will be necessary to create neat terraces of interlocking 0.54sq m boxes. But when space for these runs out, commuters should look up — to the luggage racks, so under-used at rush hour — and the space between them. Hence the ladders and hammocks, to be deployed not only in the spirit of the Blitz, but also of South West Trains’ hallowed terminus at Waterloo.