There’s a tiny mantra hidden in the chaos of cities. In its many elevators, shuttling millions towards hotel rooms with lovers & unnecessary meetings, it hums:

“Keep going as long as possible, making all the necessary stops along the way.”

That spiritually metropolitan mantra was useful in a dark morning when I wearily shuttled down to the lobby of the Dazzler Palermo in Buenos Aires. I was finally heading back to Cape Town after an 8 city, half-world trip in 45 days.

It’s the kind of trip that’s long enough that it throws out all habits you had, making it easy to forget where you were really going. The city was still dark & I wasn’t present. The fortunate memories of all I’ve yet to process in the past 45 days & the impending planes I needed to catch, left me with anxiety.

For some reason the elevator kept stopping at the first floor of the hotel even though no-one was pushing the button. It’s then that the mantra appeared again, vividly. I had forgotten. Simon:

“Keep going as long as possible, making all the necessary stops along the way.”

I: The Elevator Tango

“A door leading to an elevator in an old building in Jackson” by andrew welch on Unsplash

My elevator tango started off usually the same: the familiar pull-to-refresh on our 21st century mental fidget spinners. The feed that scrolls by feels like the city passing by: it’s there, but you don’t really digest its scenes. Moments later, the elevator dings, sounding the call for the battle to come.

I don’t know about you, but I have mild anxiety about standing in the middle of an elevator. I think it’s my primal brain being on edge to being so close to strangers with my back to them. Where possible, with head-nodding acknowledgement & aggressive politeness, it’s usually more ideal to aim for a corner.

In order to claim said corner, I have to let my new enemies know that I’m destined for it. Sheaving my Samsung Galaxy sword lets them know that there isn’t even going to be a discussion. I, the heir & rightful owner is to have no battle for the land in the corner of the elevator.

With that nod & determined gait, my enemies part as I’m able to rightfully claim it. Not content with sharing awkward glances with the non-corner, elevator proletariat, there’s really not much else to look at in an elevator, except one’s phone.

So, the familiar, habitual, pull-to-refresh comes out. Going up in the elevator & waiting for the come up from the dopamine kick. This usually works… However, most elevators are Faraday cages, blocking tweets from Kanye & Instagram photos from one’s ex.

Always forgetting this, a momentary panic sets in as I realise that in blocking access to cellular signals, the Faraday cage would leave the backdoor open to those existential thoughts you’d hope to leave locked a little longer. So, left with not being able to look at Twitter, and not having to deal with an existential crises amidst one’s new potential usurpers, there’s really only one other thought that finds its way in. In the corner of the elevator, battling with one’s demons in between floor 3 and 4, it arrives:



“Elevators. Just how the fuck do they work? How do they choose which floors to go to?”

Before I could fully contemplate the possible answers, the elevator dings like the calming sound of a Tibetan bell & I’m relieved of this physical & mental cage. This pattern is usually the same: freed to go to that hotel breakfast, rooftop drinks or sleep.

It was one particular elevator ride in the Astor House Hotel in Shanghai that I didn’t go onwards to my previously planned activities. I think the reason that the pattern stopped was that it was a particularly beautiful elevator. It was an old colonial hotel where even the elevator had wooden floors. It stuck with me. As a monsoon washed the city clean outside, I delved in.

II: Algorithms & Acolytes.

Photo by Scott Szarapka on Unsplash

My particular interest was their algorithms. How does it prioritise and choose what floors to stop at? What I found was a fascinating rabbit hole: the art & science of elevation.

The simplest elevator algorithm is:

“Keep going as long as possible, making all the necessary stops along the way.”

From an inert position, it would go where it is called. If subsequent buttons are pressed that follows in the direction the elevator is going, it will stop along all of them. During that time, even if a closer floor is called that is behind it, it will rather just keep going in the direction it was going towards.

It struck me as unexpectedly profound. Not always content with where I’m finding myself, I have to find daily reminders to bring me back to the present. Life happens everywhere, but for every actual moment, life is really only happening front of you.

Besides this new mantra, hiding in the everyday elevator, I found a field rife with passion. There’s something intoxicating about finding something where others have put in considerable amount of hard work, and especially… found meaning.

I delved deeper & found that much has been written about elevator & traffic analysis: this hidden art & science of effectively shuttling people like white blood cells through the urban organism. When it works, one doesn’t notice it: a likely unforgiving vocation. I can imagine though the joy of engineers working in this space, knowing that when people are just having a seemingly normal day, it was a success.

With uplifting eloquence, an excerpt from the foreword of the second edition of the “Elevator Traffic Handbook” by Gina Barney & Lutfi Al-Sharif reads:

“I have sat in many lectures on this subject, being beguiled as the lecturer demonstrates their mathematic skill with flawless presentations, but only to come away with more questions than answers. And so it was that I arrived at the first edition of this book, as an acolyte looking for illumination into the the mysterious world of lift traffic analysis. The first edition helped to open my eyes to the fact that, although without doubt a complicated subject, it was possible to become at least proficient, and in work through the book, to come to an understanding that, while I will never be considered an expert in the field, I can at least say that my curiosity has been sated, the blindfold removed, and my knowledge expanded to the degree that enlightenment has been achieved.”

Written by Ian G. Jones, Chairman of the British Standards Institution Committee for Lifts and Escalators & Convenor of the European Committee for Standardisation of Passenger and Goods Lifts.

Isn’t that beautiful?

Delving Deeper

Photo by Franck V. on Unsplash

I got curious about more complicated setups: larger buildings with more elevators. In talking to other elevators, do they optimise it a bit further? Turns out they do and there’s additional variants from the simplest algorithm. There’s a family of algorithms in this class, including designs like “nearest car” or “estimated time of arrival control”. The latter optimise for shortest journey time where-as “nearest car” optimises for shortest distance.

The “destination dispatch” approach is relatively modern. Instead of first pressing a direction & then inside the lift pressing the floor, destination dispatch algorithms require the floor destination first. It thus optimises the elevator’s arrival before it knows where it is going. It reminded of a quote from the film “Waking Life”, in which a man described his philosophy on life:

You want to go with the flow. The sea refuses no river. The idea is to remain in a state of constant departure while always arriving. It saves on introductions and goodbyes.

The Future of Elevation

In reading parts of the “Elevator Traffic Handbook”, it’s also clear the elevators themselves, seen as insular to its surrounding traffic, is sub-optimal. An algorithm might be on average be meaningful, but doesn’t really take into account how traffic changes during the day, or even during seasons. It is insulated from how the rest of the world functions around it.

I wondered whether machine learning or genetic algorithms have been employed to optimise for its environments, beyond just inventing algorithms that aren’t necessarily aware of how it is perhaps inadequate. If it is being used, who owns that data? Are elevator companies or building owners collecting this data?

ThyssenKrup, one of the largest elevator manufacturers maintains more than 1.1 million elevators in the world. They have been collecting data primarily to optimise when to do maintenance. A step in the right direction.

Fuzzy logic, neural networks & genetic algorithms have indeed been used. For example in the usage of neural network designs it uses perceptrons with inputs such as distance to call, current load of the car and total landings before the destination. Combining these inputs together and giving them various weights results in a decision for the car.

Genetic algorithms have also been used. These class of algorithms usually run mutations on each step to derive a solution towards a new optimum. I would assume genetic algorithms are more useful when the search space of optimal configurations become quite large. For example, it’s useful in scenarios where there are multiple elevators in a building with unique setups.

Photo by Clay Banks on Unsplash

For example, the complexity increases quite dramatically in buildings like the Burj Khalifa. It has 65 double-decked elevators, having multiple zones within it. Instead of just one car being able to serve a floor, you also now have a double-decked car being able to pack in people on multiple floors at the same time. This changes everything again. It’s regarded to be almost always more efficient than single-decked elevators. At the Burj Khalifa, they apparently also considered installing the first triple-decked elevators. Even though the Burj Khalifa seems like it could present complex arrangements to solve, it seems destination dispatch is sufficient. Sometimes to reach great heights, you clearly don’t need to invent the world to solve it.

Regardless, it’s an interesting field of research, especially considering how vertical transport fits more broadly into the future. It will become more relevant with potential futures such as driverless pods acting as hotel rooms. It’s just not people inside elevator cars anymore… it will be the cars themselves attaching & dispatching onto buildings.

In growing conurbation, it also seems that in order to design these futures effectively, it would be meaningful if these datasets would be more public. A quick search revealed that, for example, New York City serves up open data on elevator incident reports. It doesn’t feel nearly enough.

Photo by SHUJA ZED on Unsplash

A city like Hong Kong with its many tall skyscrapers in close vicinity could give us clues on how this will develop into the future. It’s known for pioneering in vertical transport, including having the largest outdoor escalators (which is awesome see btw).

Mid-Levels Escalators in Hong Kong. Source — Wikimedia Commons.

The city of Hong Kong has open datasets, but it doesn’t reveal much when searching lifts & elevators. Perhaps in the future with the rise of incentivized protocols like Ocean, we will see all this data become open and consumable by the public & other programs.

Ultimately, I feel I’m only a new passer-by, having gotten the ability to look behind the scenes into the elevator shafts of knowledge that already exists on vertical transport. There’s a lot to learn still. If you know where I & others could learn, feel free to share as responses to this article.

III: What Floor? Where Should We Be Going?

The art & science of elevators & vertical transport is fascinating and there’s a lot about it that allows us to view the world a bit differently. Besides coming to understand more of the modern miracles that make our world tick, it also seemingly allows us to find a tiny, mindful, spiritual moment in the metropolis.

The fact that it is a large part of what makes the modern world tick, yet we are mostly unfamiliar with it, makes that hidden mantra even more pertinent. Much like the hard work involved in elevator algorithm design: it’s been there all along & we just didn’t notice it. We seem to try really hard to find meaning, often trying to look beyond the veil, only to realise that what is in front of us, is the only necessary components we need.

It’s there… When you are in the elevator heading down to the lobby of a hotel in a city you don’t feel you should be. When you are in the elevator heading to a hotel room with someone you’ve fallen out of love with. When you are in an elevator heading to unnecessary meetings, the mantra is there as a reminder.

Some modern elevators can get you where you need to be, faster. The fastest journey is one directly catered for you. However, that’s only likely to happen if you arrive at the elevator alone. If there are others along with you, no matter how well designed the algorithm, you’ll have to make more stops along the way.

So: