The Mathematics of Escalators on the London Underground (2013) [pdf]

On the underground you’re meant to stand on the right of escalators to leave room for those walking up on the left. However, TFL ran a trial a few years ago instructing people to stand on both sides during peak times. This actually increased overall throughout and per-person speed: throughput as you can more closely pack passengers standing rather than allowing a smaller number of walkers half the space (and those walkers are necessarily spaced out more than standers), and per-passenger speed because even though walking up the escalator would be faster, the increased throughout reduces the queue time at the escalator entrance, which has a greater effect.<p>To my knowledge, they didn’t move forwards with keeping the instruction permanent in peak times, presumably because it’s difficult to implement &#x2F; ingrain in people.<p>EDIT: link <a href="https:&#x2F;&#x2F;www.shortlist.com&#x2F;news&#x2F;holborn-escalator-trial-tube-london-standing" rel="nofollow">https:&#x2F;&#x2F;www.shortlist.com&#x2F;news&#x2F;holborn-escalator-trial-tube-...</a>

Why doesn&#x27;t London Underground use either slowed or stopped escalators when there are no passengers?<p>I noticed in Berlin, escalators without people often run very slowly. They speed up as soon as someone steps on.<p>In Copenhagen, they stop. This is presumably more efficient, but it&#x27;s easier to assume the escalator is broken, and a bit disorientating.

There are some outdated assumptions about the carbon intensity of electricity being made here. They seem to be assuming coal-fired power emitting 0.9kg CO2&#x2F;kWh.<p>In reality, the actual average carbon intensity of the UK grid in 2021 was only 187g CO2&#x2F;kWh: nearly 5 times less! So escalators, in the UK at least, aren&#x27;t nearly as bad for the climate as this article suggests.

Why do those mathematical arguments about CO2 emitted never include how much CO2 would be emitted by a person (and transitively emitted, too - i.e. how much CO2 would be required to produce the required food for the person) if they did the job themselves?<p>I.e. somehow walking 100 steps suddenly produces 0 CO2. Which is completely not true, at least in this case the person would be breathing, let alone spending calories walking up the stairs.

Could the escalators going down generate the power for the escalators that are going up?

This is what happens when you do not use something like LaTex to typeset a paper.<p>The amount of typographical&#x2F;layout crimes screaming in your face on the first page already made me not want to read this – however curious the topic.

Honestly this is more &#x27;arithmetic of escalators&#x27; than mathematics. But now I&#x27;m curious, anyone run across some related math? Graph theory and combinatorics immediately come to mind.

Apropos, Peter Campbell on the maintenance of escalators in the <i>LRB</i>: <a href="https:&#x2F;&#x2F;www.lrb.co.uk&#x2F;the-paper&#x2F;v24&#x2F;n05&#x2F;peter-campbell&#x2F;why-does-it-take-so-long-to-mend-an-escalator" rel="nofollow">https:&#x2F;&#x2F;www.lrb.co.uk&#x2F;the-paper&#x2F;v24&#x2F;n05&#x2F;peter-campbell&#x2F;why-d...</a>.

I hope they do an analysis on the escalators in the new BER airport.. maybe we could find out the stroke of genius that designed the airport with escalators that only go up. Emphasis on stroke.

Shouldn&#x27;t a down-hill escalator be able to generate electricity?

This is urgently missing some discussion of queuing theory &#x2F; stochastic processes. Discussing passenger flow in terms of time averages is misleading, passengers don&#x27;t arrive in continuous streams. The peak load will be many times the average, which impacts power consumption, while at other times they will be running almost empty with just a handful of passengers.

Fascinating and something to think about as I ride the Piccadilly line escalators with my mind in neutral. Thanks.