The late comedian Mitch Hedberg once observed that “an escalator can never break: it can only become stairs. There would never be an ‘Escalator Temporarily Out Of Order’ sign, just ‘Escalator Temporarily Stairs. Sorry for the convenience.'” And if you think about it for a second, he’s right. All escalators are, ultimately, is staircases that move.
But as anyone who has ever tried to walk up a stopped escalator can attest, they feel different. There’s something disorienting about walking up (or down) a stopped escalator, despite the fact that the escalator is, temporarily, stairs. The disorientation only lasts a moment in some cases, but it’s real, at least for most people. Why does this happen?
One reason is that escalator stairs tend to be a bit taller than typical stairs; for example, when escalators stalled in a light rail station in the Seattle area, authorities discouraged riders from taking the stopped escalator, noting that “the rise per step is 8 inches, or an inch higher than the 7-inch-tall concrete stairs in other transit stations,” which could lead to some slips and falls. So yes, that’s part of the explanation. But there’s more.
In 2003, a pair of researchers explored the idea further. The paper is available here but the Atlantic did a great job in summarizing the experiment, so let’s use that:
To recreate the feeling in an experimental setting, the researchers used a mobile sled, which participants stepped onto from a stationary platform. First they stepped onto the sled 10 times while it wasn’t moving, then stepped onto it 20 times while it was in motion. Then the researchers stopped the sled, clearly told the participants it wouldn’t be moving, and had them walk onto it again.
In theory, that last time stepping onto the platform should have been identical to the first ten — in all 11 cases, the participants were going from a stable platform to a stopped sled. But that’s not what happened. Per the paper, the subjects tended to approach the once-moving-now-stopped platform a bit more quickly and did so using a more apprehensive step forward (as measured by torso movements) when they ultimately stepped onto the platform. Many subjects told the researchers, anecdotally and unprompted, that they felt similarly to when they had stepped onto a stopped escalator. And as no stairs were involved, the rise of the stairs doesn’t matter. Something else was going on.
The research team’s theory boils down to muscle memory. When we do things like walk or run, we’re on autopilot in a sense — our brains are telling our legs and knees and feet to take steps, but we do so at a subconscious level. We don’t have to consciously decide which muscles to contract or even how long our strides should be. It just kind of happens.
As a result, even though our conscious selves know that the broken escalators ahead of us are just temporarily stairs, our unconscious motor systems don’t really care to process that information fully. Yes, we adapt slightly, but by and large, the motor system simply approaches the escalator as if those stairs are going to start moving. A few steps in, we compensate for this mistake, but at that point, the odd stair height or staircase angle keeps the walk disorienting.
So if you’ve ever struggled with a stopped escalator, don’t feel bad — you’re not alone. If anything, you’re just outsmarting yourself.
From the Archives: Let’s Talk About Escalators: And why you won’t find many in Wyoming.