Why are Salt Lake City’s airport moving walkways so slow? Is there anything that can be done about that?

Well, cool your heels, all you impatient flyers. Turns out, there are lots of rules, costs and other considerations before cranking up those speeds.

(Rachel Rydalch | The Salt Lake Tribune) Travelers using moving walkways at the Salt Lake City International Airport in Salt Lake City on Thursday, Jan. 27, 2022.

There’s nothing better than having a small gripe.

With a small gripe, you get to feel aggrieved for reasons that don’t really make your life worse. You can blow it out of proportion. You can, with a constant tinge of irony, rant and rave about a tiny beef. Crotchety old men have it right — complaining just feels good.

I have a small gripe: The moving walkways at the Salt Lake City International Airport are too slow.

At my last trip walking through the airport, watching as those off the moving walkway were moving faster than those on it, I decided to pursue this story. Frustrated as I was by my small gripe, I did the only thing I know how to do: I researched it. I’ve spent an embarrassing amount of time recently learning about moving walkways. I learned about the moving walkway industry as a whole, the way in which the walkways work, the laws governing them, and, critically, the speeds at which they operate. And I learned about some potential solutions to the problem.

I figured I’d share that information with y’all, because I know I’m not alone in my frustration. In doing so, I think I’ve written the definitive moving walkway story available anywhere. Is this too much detail about such a small gripe? Perhaps. But I want you to know what I know.

Intro to moving walkways

(Rachel Rydalch | The Salt Lake Tribune) The new airport is much bigger than the old one, which has meant a lot of walking.

It turns out that the airport moving walkway industry is a big one: one source estimated that about $2 billion worth of moving walkways were sold to airports in 2020, and that there would be about $3 billion by 2030.

Salt Lake City’s airport was a portion of that. All in all, the airport has spent $19 million on the contracted moving walkways, which are located in the gateways, the bridges, the parking garages, and of course, the terminals. That $19 million includes the currently installed moving walkways, and the ones to come in the Concourse A East expansion, the central tunnel, and the first phase of the Concourse B East expansion.

Those walkways are all made by Schindler, an originally Swiss company that also has an American division. They’re all model 9500 walkways, between 170 feet and 300 feet long, all 48 inches wide. All but four of them require substantial pits underneath the entrances and exits of the walkways, where the machinery pulls the walk along on one end and creates tension on the other.

Diagrams of the Schindler 9500s — the moving walkways at Salt Lake City International Airport — and how they operate. (https://us.schindler.com/content/dam/website/us/docs/moving-walks/schindler-9500-horizontal-moving-walks-brochure.pdf/_jcr_content/renditions/original./schindler-9500-horizontal-moving-walks-brochure.pdf)

You’ll notice the 4-foot pit depth required at the edges, and about 13 inches in the middle — that’s more than I would have thought, but is pretty typical of moving walkways in general.

Four of the airport’s moving walkways are called “pitless” versions, in which a minimal pit is required, and the walkways are somewhat raised. Those four are all in the bridges connecting the airport with the passenger pickup locations, because a 4-foot pit in a bridge just can’t work. But pitless systems are more expensive and require more upkeep.

All of the airports’ currently installed moving walkways combined use about 1,058 kBTU per hour when being operated. They do, though, have energy-efficient sensors that turn them to lower speeds when no one is either on or approaching the walkway.

Last week, the airport posted a picture of one of the new walkways being installed in the new Concourse A East.

(Salt Lake City International Airport) Installation of a moving walkway in January of 2022 in the Salt Lake City International Airport's Concourse A east expansion.

They move these walkways into the building before it is closed. They ship mostly assembled at the full length of the walkway, so they’re too big and wide to move in through the doors.

The problem

As has been endlessly documented, the new airport is much bigger than the old one, which has meant a lot of walking. This is a bummer for most travelers but especially the old, the young, the disabled and so on. It used to take just a couple of minutes to get to your gate when flying out of Salt Lake City. Now, you might have to walk two-thirds of a mile.

This takes time. The airport put together these estimates of how long it takes to walk from the terminal to the farthest gates.

(Christopher Cherrington | The Salt Lake Tribune)

Here’s my gripe: The moving walkways hardly help at all. To the end of Concourse A, they save the moving-walker less than a minute. To the farthest point at the end of the airport in Concourse B, it saves just about a minute and a half.

That’s because the moving walkways just don’t move that fast. Indeed, they move quite slowly. The speed of Salt Lake City’s moving walkways is 100 feet per minute — or, in terms you’re actually likely to recognize: 1.13 mph.

That’s also about the speed that icebergs travel. It is roughly a fifth the speed of a swimming crocodile, a fourth the speed of a jellyfish. Koalas climb trees about 50% faster than the moving walkways move horizontally.

But wait, it gets worse.

Seth Young, director of the Center of Aviation Studies at Ohio State University, conducted a 1999 study at the San Francisco and Cleveland airports to watch how people were using moving walkways. He found that people generally walked 3 mph in the airport when not on a moving walkway (a number that correlates really well with the results of a 1978 study that found a 3.01 mph walking speed in New York City transit situations).

But when people got on the moving walkway, their walk slowed down: They walked only about 2.2 mph. The walkways that Young studies were moving at a brisker 1.4 mph pace, which means that these passengers traveled at 3.6 mph. It’s clear, though, no matter the speed of the walkway: Even when ignoring the people who stop and stand, most get only a marginal benefit from the moving walkway.

There is a clear inverse correlation between the speed of the walkway itself and the speed that people choose to walk; the faster the moving walkway goes, the slower people will choose to walk on average. One industry study — I found this in a ThyssenKrupp brochure — found the peak capacity of moving walkways occurs when they move 145 feet per minute. Still, that’s 1.64 mph, significantly faster than Salt Lake City’s moving walkways.

Estimated passengers/hour on a moving walkway as a function of how fast the moving walkway goes. (https://sweets.construction.com/swts_content_files_nas/43184/432947.pdf)

So why are the airport moving walkways so slow? I’ll let Cal Smith, deputy program director of implementation at the airport, explain.

“In airport use, where you have a lot of people with children or baggage, getting on and off the moving walkway are a safety concern — for the moving walkway companies like Schindler and ThyssenKrupp, and moving walk consultants,” Smith said. “They try to limit the speed for those areas due to safety concerns.

“People are fumbling. They’re trying to get their grip on the entries and exits,” Smith added. “Particularly for elderly or for challenged people who are trying to use those moving walkways — moving walkways are there for everybody, able-bodied and not so able-bodied.”

Now, what kind of accidents happen? Sometimes, the walkways can grab loose clothing. In 1960, a 2-year-old girl died on a moving sidewalk when her coat got trapped at the edge.

Safety measures clearly have improved since then. There’s a somewhat humorous example diagram in the Schindler 9500 brochure of a high-heel shoe tip getting caught — an incident that the manufacturer said was now a thing of the past, thanks to additional safety measures along the walkway’s edge.

The moving walkways installed by SLC's airport have preventative measures against high heels — or other loose clothing — getting stuck. (https://sweets.construction.com/swts_content_files_nas/43184/432947.pdf)

Trips and falls do still happen, though. In 2017, a Dallas airport passenger fell when a walkway stopped, causing a dislocated shoulder. It appears that, in 2010, a 58-year-old woman fractured her wrist exiting a walkway.

There’s no database for moving walkway injuries, but I did think it was notable that searching for the phrase “moving walkway accidents” led to more results for attorneys who will help you sue a moving walkway company than for actual published accounts of moving walkway accidents.

I haven’t been able to find any data regarding the relationship of walkway speed to walkway injuries, either. I suspect that such a relationship would be tenuous, given how few moving walkway injuries seem to occur. Truthfully, what I believe is that the companies’ and consultants’ recommendations to set the walkways at 1.14 mph is more about avoiding those attorneys than avoiding those injuries — but that’s guesstimated commentary, not research.

Is the solution coming?

So I asked the airport: What if I get Utahns on board with the idea of speeding up the walkways? After all, we weren’t afraid to boost Interstate 15′s speed limits. Couldn’t we raise the speed of these walkways?

And just imagine what would happen if we could get more people through the airport more quickly. It’d be great for those travelers’ lives, sure, but it could also lift the economy. Imagine having a couple of extra minutes to get a snack, a drink, or to spend a moment browsing at an airport store. Heck, we can’t afford not to speed up the walkways!

Well, Smith told me, not so fast. While the Schindler 9500s that the airport has can operate faster — Smith threw out a 130 feet per minute speed, or about 1.5 mph — they would need new parts to do so. The motors and drive units that power the walkways currently perform at the slower 1.13 mph, and it’s not a matter of turning a knob to speed them up. It would be an expensive and time-consuming project to replace those motors, and, of course, we’d have the walkways not work at all while those changes were being made.

If you’re like me, you were probably disappointed with even the idea of 1.5 mph being the “fast” setting. That’s all we can do? Actually, it turns out we can do better.

Introducing the accelerated moving walkway. These, manufactured by ThyssenKrupp, go that same slow speed on the edges, so that people can easily enter and exit the walkway, but then accelerate in the middle to a maximum of 7.4 mph. The video shows how they work: basically, the walkway inserts little pallets in the middle that accelerate the person to top speed as they walk. It is exceptionally cool.

Turns out that there’s only one of these in North America: at Toronto’s Pearson International Airport, where there’s a 1,000-foot bridge that needs to be traversed. I’ve had the privilege of riding this. It’s a game changer. It turns a 10-minute walk into a 3- to 4-minute one. It also just feels neat to be whisked from one place to another safely.

Smith, our Salt Lake City airport source, was familiar with the project. He had worked in Toronto’s airport, and met his wife there. She worked on the team that installed the accelerated moving walkway. What a love story!

I asked him: Why not install this in the 1,200-foot central tunnel between the A and B concourses?

Well, turns out that it isn’t legal by most U.S. standards. Code regulations say that a moving walkway can only go up to 180 feet per minute, or about 2 mph. But even if the code were to change — and I think a lobbying effort could succeed — there are other considerations.

For example, code also states that people can’t be trapped on a walkway where they have to move in more than 200 feet in either direction to get out. That’s one reason why the walkways at the airport are all limited to under 400 feet. The accelerated walkway at Toronto actually has movable arms at the entrance, almost like a railroad crossing, that prevent people from getting on the walkway in case of a fire or other emergency.

From the video, you can see the accelerated moving walkway’s handrail is a bit wonky — it works less smoothly than the underfoot tread, creating hand pinching opportunities. It’s also pretty noisy, and breaks more often, thanks to all of those moving parts.

“When we travel to Toronto,” Smith said, “we’re very excited because we love (the walkway). “It’s like, ‘Oh, we get to use the high-speed moving walkway, this is fantastic! Sometimes we’re really happy and we’re on that thing and we’re speeding down there. And sometimes that doesn’t work and you’re just going, you know, 1.4 miles an hour and you’re like, ‘Oh, I wish it was working today.’”

It reminds me of another advance in air travel technology that seemed like the wave of the future: the Concorde. Remember the supersonic aircraft, of which 20 were built? It could fly people from Paris to New York in under 3.5 hours, when a normal flight takes eight. It clearly was a step forward. Just like Toronto’s accelerated moving walkway, it also was noisy, expensive, and broke often, and so didn’t get widely adopted after the initial aircraft.

The more likely solution to Salt Lake City’s biggest walkway speed problem, though, is an automated people mover — essentially an underground train connecting the concourses. At the moment, that’s not scheduled to be built until decades down the road, when the airport needs to expand to a future Concourse C.

Debate continues, however, and airport officials acknowledged that it’s possible it could be built sooner if the public demands it and funding can be established.

But for now, the plan is plain and slow Schindler 9500s moving at 1.13 mph through the central tunnel. Those walkways would be wider (56 inches) than the others at the airport, and a bit longer. Still, it’s not the improvement I desired.

Some other fun moving walkway facts

(Rachel Rydalch | The Salt Lake Tribune) An underground train connecting the concourses is not scheduled to be built until decades down the road.

While we’re here, I might as well tell you some other moving walkway facts that I learned while reporting on this article.

First, Young’s study on the speed on which people walk on moving walkways was full of fascinating results. Some likely won’t surprise you. Business travelers, on average, walk faster than leisure travelers. Men, on average, walk faster than women.

But do people walk faster when entering the airport or leaving the airport? Turns out, those moving away from the gates move faster on average than those going to their gates — despite the few folks who are running, trying to avoid missing their flights. Everyone else, seemingly, is in less of a mood to move quickly when they’re about to board a flight.

Meanwhile, people with bags actually move faster, on average, than those without bags. This may have to do with the tendency of those who would be burdened by bags to check them before using an airport’s moving walkway.

In Young’s study, about 20% of people just stood on the moving walkways — remember, his traveled at the faster 1.4 mph speed. However, among those who do walk, most (80% of walkers) won’t go out of their way to pass a stopped traveler if he or she is blocking the walkway.

Finally, a sad note: Some airports have actually removed their moving walkways altogether in the past decade, usually because they’re simply using too much space in airport terminals that are becoming more crowded. In trouble spots, they intersect with lines of people at gates waiting to board, causing havoc. For these reasons, Chicago’s O’Hare removed moving walkways in one United concourse, as has Las Vegas’ airport. Cincinnati’s airport removed some of its walkways, simply saying that they were too expensive to replace.

But there are still moving walkway fans out there. A group of seniors, for example, complained when Orlando’s airport proposed removing them, calling them a “godsend” and a “saving grace.”

I’ll join them. Bless moving walkways. I hope for their continued existence in our lives. I just also hope that they start to high-tail it.

Andy Larsen is a data columnist for The Salt Lake Tribune. You can reach him at alarsen@sltrib.com.