The idea had come about after Len Lau, Vauxhall area manager, had gone to Hong Kong on holiday. Lau noticed that passengers on that citys Mass Transit Railway (MTR) were standing calmly on both sides of the escalator and, it seemed, travelling more efficiently and safely as a result. His report prompted Harrison and her colleagues to wonder whether the same effect would apply at a station such as Holborn, and so they set about arranging a three-week trial.
The theory, if counterintuitive, is also pretty compelling. Think about it. Its all very well keeping one side of the escalator clear for people in a rush, but in stations with long, steep walkways, only a small proportion are likely to be willing to climb. In lots of places, with short escalators or minimal congestion, this doesnt much matter. But a 2002 study of escalator capacity on the Underground found that on machines such as those at Holborn, with a vertical height of 24 metres, only 40% would even contemplate it. By encouraging their preference, TfL effectively halves the capacity of the escalator in question, and creates significantly more crowding below, slowing everyone down. When you allow for the typical demands for a halo of personal space that persist in even the most disinhibited of commuters a phenomenon described by crowd control guru Dr John J Fruin as the human ellipse, which means that they are largely unwilling to stand with someone directly adjacent to them or on the first step in front or behind - the theoretical capacity of the escalator halves again. Surely it was worth trying to haul back a bit of that wasted space.
Paul Stoneman, one of Harrisons colleagues, did some preliminary calculations. In theory, he found, getting people to stand on both sides would mean that 31 more passengers would get on to the escalator each minute an increase of 28%. Holborn seemed like the perfect test case, not only for the rake of its escalators, but also for its rush-hour stampede: When you come round the corner and see this throng, says Stoneman, you just go, blinking flip, I dont want to use this station, its a nightmare. Its like Bank. But success was by no means a given: as Lau also noted, commuters in Hong Kong are vastly different to British ones. In a wash-up meeting to analyse the results of the trial a few weeks after it was completed, Stoneman asked the dozen people in the room: How many years have we been saying, stand on the right? Its quite a significant behaviour to change.
