Beyond the 99% Invisible City

From rogue stop signs to rooftop mini golf, discover how chaos and creativity quietly shape the urban world.

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Roman Mars?

  Instagram teen accounts have automatic protections on by default. Built-in content settings for the content teens can see, contact limits for who can contact them, and time management tools like daily time limits and sleep mode. Teens are automatically placed into teen accounts, and teens under 16 will need a parent's permission to change any of these settings to be less strict. Instagram will continue adding built-in safety features to help create age-appropriate experiences. Learn more about teen accounts and Instagram's ongoing work to protect teens online at instagram.com/teenaccounts. This episode is presented by Air France. Air France Business Cabin offers comfort from start to finish. Enjoy priority check-in and boarding, followed by access to peaceful lounges.

• 0:45Roman Mars?

  Onboard, savor menus created by renowned French chefs paired with wines and champagne selected by Smollet. Stay connected with free high-speed Wi-Fi. Then unwind in a fully adjustable lie-flat bed with a mattress topper developed with Sofitel My Bed, a signature touch of French hospitality. The art of travel elevated because Air France Business Cabin goes further in every detail to make your journey exceptional. 99% Invisible is presented by Acura. Curating and designing the perfect experience takes meticulous craft, an obsession with detail, and a love for innovation. Just like museum designers, Acura carefully considers every detail

• 1:29Roman Mars?

  to curate the most engaging, exhilarating, and rewarding experience for drivers. That craft isn't always something you can see, but it's something you'll feel, that flutter in your heart, the engine roars. Every Acura is designed with deliberate intention around how people actually use the vehicles. And that is precision-crafted performance.

• 1:53Speaker 01

  This is 99% invisible. I'm Kurt Kohlstedt.

• 1:57Roman Mars?

  Okay, so like, what I want you to do is I want you to take a breath, take a breath, okay? And just like, you know, just get into your voice a little bit and go, "This is 99% invisible. I'm Kurt Kohlstedt."

• 2:12Speaker 01

  This is 99% invisible. I'm Kurt Kohlstedt.

• 2:16Roman Mars?

  Okay, now I want you to, no, no, no, no, no, I want you to do it again.

• 2:20Speaker 01

  Okay.

• 2:23Roman Mars?

  And I want you to do it now this time, like, I want you to do, the gravitas is there, like, you're getting like that part of the tone, but I want you to add, once now that you have that, I want you to add like a little bit of smile in your voice. Okay?

• 2:36Speaker 01

  Okay.

• 2:36Roman Mars?

  So you're gonna go, "This is 99% invisible. I'm Kurt Kohlstedt."

• 2:41Speaker 01

  This is 99% invisible. I'm Kurt Kohlstedt.

• 2:45Roman Mars?

  That's great. I love it. Print it.

• 2:53Speaker 01

  In 2020, my co-author, Roman Mars, and I put out a hit book about the built environment. It's an illustrated hardcover we called "A Field Guide to the Hidden World of Everyday Design."

• 3:04Roman Mars?

  "The 99% Invisible City" was an instant New York Times bestseller and topped the charts in the UK, Canada, and Australia.

• 3:11Speaker 01

  Versions of the book were also released in other countries as well, translated into languages including Spanish, Czech, Chinese, Korean, and Japanese.

• 3:20Roman Mars?

  In the years since these first edition releases, Kurt and I have worked together on a number of new episodes and many stories with an eye towards an eventual second edition, a kind of revised and expanded paperback iteration with additional as-yet-unprinted stories.

• 3:35Speaker 01

  But today, rather than wait on publishers or printers, we've decided to share a set of four of our favorite short stories from the past half-decade, each of which corresponds to one of the four main chapters of "The 99% Invisible City."

• 3:50Roman Mars?

  And those chapters are: infrastructure, urbanism, geography, and architecture. So if you enjoy what follows, be sure to check out both the book, "The 99% Invisible City", and the original episodes associated with each short story.

• 4:03Speaker 01

  That's right. Let's get started.

• 4:06Roman Mars?

  Infrastructure.

• 4:08Speaker 01

  Shortly before the book came out, but after the final draft was already locked in, Roman and I did an episode on roadway signs and other roadway infrastructure designs. We titled it highways 101. And what started us down this road was a letter from a fan.

• 4:26Roman Mars?

  One of the things Kurt does is he checks our inbox for listener submitted ideas, combs through all of them. And earlier this summer, a 99PI fan named Daniel wrote us about a strange stop sign that he encountered while traveling. And you started digging into this story.

• 4:41Speaker 01

  Yeah. So, so his email started like this. A couple of years ago, we took a trip to Hawaii. My wife became obsessed over a few blue stop signs we saw in parking lots. The signs were the size and shape and used the same lettering as normal red stop signs, but they were bright blue.

• 5:00Roman Mars?

  So I don't think I've ever seen that before.

• 5:02Speaker 01

  I had never seen this either, either in images or in real life. So I started looking into why some were blue. And that turned out to be pretty easy to figure out, but it got me wondering something a lot more fundamental, which is why are the rest of them all red? Right? Like, why is that such a thing in the first place?

• 5:21Roman Mars?

  Totally.

• 5:22Speaker 01

  Yeah. And that got me into, of course, digging into the whole history of stop signs.

• 5:26Roman Mars?

  Of course, of course. That's the only way this is going to go with you.

• 5:29Speaker 01

  Yeah, it's just my nature. And as I was looking into this, this one figure kept popping up everywhere I looked. A guy named William Phelps Eno, who in the early 1900s became known as the father of traffic safety.

• 5:45Roman Mars?

  Oh, okay. So what do you have to do to earn that title, the father of traffic safety?

• 5:49Speaker 01

  So Eno was born way back in the 1850s. And if you think about it, you know, 1850s, he's in New York. This is a New York without cars.

• 5:57Roman Mars?

  Right.

• 5:58Speaker 01

  So of course it's a New York without stop signs.

• 6:01Roman Mars?

  Without stop signs, totally. Yeah. The roads back then were kind of this open space that was shared by carriages and pedestrians and they moved all around. It was a lot different.

• 6:09Speaker 01

  Right, right. It wasn't very organized. More and more people were on the streets and, you know, cars started showing up. And it just was increasingly clear that This was a mess and it was going to need some kind of regulation.

• 6:24Roman Mars?

  And so was you know, some kind of road expert? Is that what he was working on?

• 6:27Speaker 01

  Well, that's the thing, not really. He, he came from this family real estate business, decided it wasn't for him. Wasn't his passion. His passion was traffic. So in 1900, he writes this article. And it's not entirely clear in hindsight if he realized what he was doing at the time. But he basically was writing a treatise that would lay the groundwork for everything he would do for the rest of his life. So in the end, he would come around to, you know, inventing and evolving all different kinds of traffic innovations. Things we take for granted today, like rotary junctions and pedestrian crossings.

• 7:06Roman Mars?

  Wow. So he really earned that title, the father of traffic safety.

• 7:09Speaker 01

  Absolutely. And once his ideas got some traction in the US, he began helping other cities create traffic plans. And some really recognizable designs traced back to him, like roundabouts at Piccadilly Circus in London. And around the Arc de Triomphe in Paris. And he was even inducted into the Legion of Honor by the French government after World War One.

• 7:34Roman Mars?

  For traffic?

• 7:35Speaker 01

  Yes.

• 7:36Roman Mars?

  That's where he got that. Wow. And so was Eno the man who invented the stop sign?

• 7:41Speaker 01

  Well, that's the thing. I kind of fell down this rabbit hole of looking into him. But one thing I realized along the way was that I was never going to find the inventor of the stop sign.

• 7:53Roman Mars?

  Yeah.

• 7:53Speaker 01

  Because it's one of those things that has existed in various forms for a while now. But it's safe to say that Eno played a really big role in popularizing stop signs and yield signs and, and that kind of signage. Infrastructure. And also, you know, put this in context, right? Stop signs back then, they weren't what we think of as stop signs today. Their designs varied from place to place. Uh, one of the first ones that popped up in Detroit in, I think it was 1915. Had black lettering on a white background, presumably for contrast. So they really, they came in all these different shapes and sizes. And there was no sort of one person you could say, aha, that guy made the stop sign.

• 8:37Roman Mars?

  Yeah, I mean, I think that makes sense to me that there would be a need for stop signs and therefore they would be invented in multiple places and multiple times. So when did they sort of get this octagonal shape that we attribute to them? Like, when did that happen?

• 8:52Speaker 01

  Right, so that one actually does have a specific answer. And the answer is 1923. That's when the Mississippi Valley Association of State Highway Departments decided to standardize the shape.

• 9:05Roman Mars?

  That's a very specific answer.

• 9:06Speaker 01

  Yeah. And it was a pretty good idea to make it a non-standard shape, something that would stand out. But there was actually more to it than that. They had this idea that they could create an association between geometry and safety.

• 9:25Roman Mars?

  Explain more what you mean there.

• 9:27Speaker 01

  Well, they believed that the shape itself could communicate something, like part of what the sign was trying to do could be achieved through the shape of that sign.

• 9:38Roman Mars?

  Okay, so then we're not talking about just associating a rare shape with a specific meaning. They actually, there's some kind of theory behind eight having a meaning that ties to stopping.

• 9:51Speaker 01

  Yes, and this was a huge surprise to me.

• 9:55Roman Mars?

  Yeah, because it sounds like nonsense.

• 9:57Speaker 01

  It sounds right. It sounds sort of occult almost, right?

• 10:01Roman Mars?

  Totally.

• 10:01Speaker 01

  But I found this out through this New York Times Magazine article by Hillary Greenbaum and Dieter Rubenstein. And I'm just gonna have you read this excerpt for context that explains why the Highway Departments Association recommended different shapes for different signs.

• 10:20Roman Mars?

  Okay, here it is. Quote, "The recommendations were based on a simple, albeit not exactly intuitive, idea. The more sides a sign has, the higher the danger level it invokes. By the engineer's reckoning, the circle, which has an infinite number of sides, screamed danger and was recommended for railroad crossings. The octagon, with its eight sides, was used to denote the second highest level. The diamond shape was for warning signs, and the rectangle and square shapes were used for informational signs." End quote. That is just wild.

• 10:54Speaker 01

  It really is, right?

• 10:56Roman Mars?

  I mean, there's so many things that I have, so many questions I have about this, and one of which is like... It's a circle really have an infinite number of sides?

• 11:04Speaker 01

  Yeah, so I'm thinking back to like, you know, grade school geometry and I'm like, I think that there's something to that. I think it's like,

• 11:11Roman Mars?

  Yeah, if you take the tangent of each point and therefore it has an infinite number of sides. But I don't think people perceive it as having infinite numbers. I think they perceive it as having one side.

• 11:21Speaker 01

  Right. It's not like we look at a circle, a square and a triangle and we say, aha, right. Three, four and infinite.

• 11:30Speaker 01

  It never in a million years occurred to me that there was some grand geometric theory behind US stop sign shapes. But if you think about it, if you start to unpack it and you look at signs around you, you can sort of understand what they're getting at, right? It's like, well, yeah, rectangular signs often tell you like what exit to take or something. There's circles at railroad crossings. Sure.

• 11:54Roman Mars?

  Yeah, but there's also like arm bars at railroad crossings, you know, like because the circle is not quite enough. Sometimes there's also X's and R bars and all kinds of other things. So I get that there's a theory behind it. And if it has some kind of basis and semiotics, I'm willing to entertain that notion. So now that, you know, in 1923 in Mississippi, they established the shape. How did they come up with the red background?

• 12:17Speaker 01

  Well, that might seem like the simpler decision. That would actually took a while longer. At the time, yellow was often used in part just for material science reasons. Like they couldn't get a really good reflective durable red. And so yellow showed up at night. So for decades, that was the general standard. And then in the 1950s, they made red the official standard.

• 12:41Roman Mars?

  Okay, so yellow, because you can make kind of a matte yellow and it contrasts really well with with black, for example, when it looks really good at night. But until you get that shiny red that you see on a stop sign, red is not a very good stop sign color.

• 12:56Speaker 01

  Right. And if you think about like, when you see a red stop sign at night, it is really shiny and really reflective. And also by, by that time too, you know, we've got stoplights and other signage. And red has really got this built up association of being a thing telling you to stop. So making the red just kind of fit with the grander scheme of, of everything else that was going on at the time.

• 13:21Roman Mars?

  Yeah, and it's a warning color in nature. I suppose yellow is too, but yeah, it makes it makes sense. So how does this, you know, get us to those blue stop signs in Hawaii that Daniel found?

• 13:31Speaker 01

  Oh, right. And that's how we come full circle or full octagon, as it were. And it turns out the blue painted stop signs are actually exceptional on purpose. You usually find them on private property, places like store parking lots. And the reason they're blue is so they won't be confused with other official government red signs.

• 13:55Roman Mars?

  That makes sense. So they're like intentional fakes because they don't want it to seem like it's a sign maintained by the city or county. So they're like mall cops.

• 14:05Roman Mars?

  They have a badge. They might have a gun, but they're they're not actual cops.

• 14:09Speaker 01

  Yeah, right. Like whether you actually decide to pay attention to what the sign's telling you is a little bit up to you. But it is really clear what it's trying to tell you, right?

• 14:19Roman Mars?

  Yeah, I mean, that's one of the things I think it's so great about the stop sign is that with the shape, the word stop and the color, you can really take one or two of those elements. And at this point, it'll convey the meaning. Like if you had a red octagon with no word stop on it, I think people would generally stop.

• 14:37Speaker 01

  Right. Or if you saw, you know, an octagon from behind, you'll know that that's a stop sign.

• 14:43Roman Mars?

  The other people have to stop. Yeah, totally. Yeah. Well, that's a, you know, that's a good sign. So they were onto something in Mississippi in 1923 and they figured something out.

• 14:59Roman Mars?

  Urbanism.

• 15:00Speaker 01

  During the COVID pandemic, I became interested in how other global disasters had historically impacted urban design. And my research yielded not only stories of white knuckled perseverance and resiliency, as you'd expect, but also tenacious creativity and playful innovation. So I pitched Roman on a Horseman of the Apocalypse themed episode titled War, Famine, Pestilence, and Design. And that might all sound very serious, and a lot of it is, but. And that's when I came across the rise of miniature golf during the Great Depression of all times.

• 15:43Roman Mars?

  That is not an association I would have paid. So when I picture miniature golf courses, I kind of think of like the World War II era, you know, like sort of kitsch leisure and baby boomers and that kind of thing, not the Great Depression.

• 15:53Speaker 01

  Yeah, right. I mean, the last thing on your mind when you look at a mini golf course is the worst economic crash in modern history.

• 16:02Roman Mars?

  So did mini golf come up because like it was too expensive to maintain, you know, big fancy golf courses or something like that?

• 16:10Speaker 01

  I mean, that's part of it, right? There's no way you're going to maintain these huge grounds for just a couple of people walking along with their golf clubs and like all that we associate with sort of luxurious sprawling golf courses. That was kind of not on the agenda financially, but also there's just the matter of space, right? You've got all these people who are in cities and need something to do. And, you know, they don't have transportation to get out of cities. So mini golf becomes this kind of logical solution, kind of infill solution in the urban environment.

• 16:41Roman Mars?

  Right. So like along with everything else, real estate prices plunged and there's some space and you might, you know, if you have a little bit of space, you can build, you know, a miniature golf course.

• 16:51Speaker 01

  Yeah, that's exactly it. The conditions were in some ways totally ideal in the wake of 1929 for exactly this kind of activity. And so while technically mini golf actually predates the stock market collapse, the crisis really ramped up interest in it. And you have, as you noted, like tons of closed businesses and vacant lots and, you know, all of this is just ripe for entrepreneurs to take over. And even in places where there's not extra space, people just kind of made space, like they would convert rooftops into PB golf courses or parking lots, really anything. And so it was this surprisingly huge fad. And at one point, somebody even called it the madness of the 1930s.

• 17:33Roman Mars?

  Specifically talking about miniature Pee Wee Golf is the madness in this phrase.

• 17:38Speaker 01

  Yep, absolute insanity.

• 17:40Roman Mars?

  That is, that's quite the sequel to the roaring twenties.

• 17:44Speaker 01

  Yeah. And so you've got these two very different periods in a way, but there's also this parallel where if you think about it, everybody needs recreation and distraction and it doesn't matter if things are going well or they're going horribly. And given the economic situation in the 30s, cheaper activities were naturally much more appealing. So on the business side, it's also an opportunity, right? Because people could turn their own yards into courses or the interiors of their unused office buildings. Basically, anybody could try their hand at building a course. And so tons of people did.

• 18:15Roman Mars?

  Wow, I love picturing that, that people are just entrepreneurially like setting up a miniature golf course, like a lemonade stand, like everywhere they can. So when did all the things that I think of when it comes to miniature golf crop up, like the, you know, the mechanical windmills or the ramps and, you know, all that sort of stuff? When did that happen?

• 18:34Speaker 01

  So some of the more technologically advanced stuff came later, but a lot of those basic things that we still see in miniature golf courses today do date back to this exact era. Things like ramps and bridges and ridges, people just build out of like available dirt or whatever they could find. And at the same time, you have this recent invention of artificial turf, which helps courses hold up better to foot traffic. So people who could afford it would add that to make a more robust course. But, you know, really the kind of key in all this is all the odds and ants. Course makers could just grab whatever scraps they could find, pipes and stones and just work them into this bigger design. And there was some

• 19:15Speaker 01

  scrappy entrepreneurialism in picking the sites for these places too. Like some would situate their courses underneath big lit up billboards so that they could operate at night without having to pay for, you know, the light bulbs or the electricity.

• 19:31Roman Mars?

  Oh, I love it. This is so fun to picture like cities filled with miniature golf courses everywhere. I mean, am I getting this right? Is it really like, like everywhere?

• 19:41Speaker 01

  Yeah, I mean, I've literally seen pictures of it being everywhere. And like, I love these images of like little rooftops that are where people are crowded around like playing mini golf. And, you know, it's totally the opposite of what we can imagine today, right? Like you look at New York City and you think, well, every bit of real estate is used and expensive. But back then it was like, no, there were, there were little spaces you could cram into. And so people would just head out in droves and go play mini golf.

• 20:06Roman Mars?

  Wow. I mean, mini golf is delightful. So it doesn't surprise me all that much. But the ubiquity of it that you're describing really is striking.

• 20:15Speaker 01

  Yeah. And of course, with all these creators vying to make their course the best course, trying to attract, you know, more players, there was innovation around that, too, like ways that people would try to set theirs apart. Things like pools and mazes and traps popped up. And eventually, you know, more kind of fancy things like fountains and forests and castles, and even replicas of famous architecture, like the Taj Mahal or the Great Wall of China. And so over time, these things become almost like tiny theme parks, right? Like just populated with all kinds of wild and creative and colorful stuff. And this one in particular that I read about, I think is has my personal favorite feature, which is a trained monkey that goes

• 20:59Speaker 01

  after your ball. So if you're not careful, it'll just come and snatch your ball and it's like game over.

• 21:07Roman Mars?

  I would definitely go to that park.

• 21:09Speaker 01

  Oh, yeah. Yeah, I wish that one was still around today. But a lot of the elements are still around, right? Like, like those complex courses with the miniature architecture, it's like become a kind of staple. And it's still like this thing that we associate with like a fun family night out.

• 21:24Roman Mars?

  Totally. It's just sort of fun to imagine New York City just being carpeted with miniature golf courses of all things. I just, I kind of love it.

• 21:32Speaker 01

  Oh, I do too. I do too.

• 21:39Roman Mars?

  Geography.

• 21:41Speaker 01

  99% Invisible has a recurring episode series we call Map Quests. Each new installment collects geography-related stories from different producers. In some cases, a given collection might revolve around a specific place or typology. And one such set, named 5440 or Fight, came out during the COVID era, and it contains a set of stories centered on the border between the United States and our country's affable neighbor to the north.

• 22:11Roman Mars?

  And you have a Canadian border story for us?

• 22:13Speaker 01

  Oh, I do.

• 22:14Roman Mars?

  Okay, hit me.

• 22:15Speaker 01

  It's about this pair of adjacent parks that are along the US-Canadian border in Blaine, Washington and Surrey, British Columbia. And in these parks, like right where they meet along the border, there's this big peace arch monument with this inscription, "May these gates never be closed."

• 22:35Roman Mars?

  Wow, well, that's a pretty bold statement for a border.

• 22:39Speaker 01

  Right?

• 22:40Roman Mars?

  Which is like antithetical to what borders are usually about. So what's the story there?

• 22:45Speaker 01

  Well, the arch and the parks date back to the early 1900s, but that never-closed sentiment is actually a nod to the War of 1812 between the US and the UK. And at the end of that conflict, basically, both sides signed a treaty to leave the border between the US and Canada undefended as a sign of friendship.

• 23:05Roman Mars?

  And so now there's this arch with this sentiment written on it. But I mean, can you truly walk through it whenever you want?

• 23:11Speaker 01

  Well, yeah, for most of the past century, you absolutely could. And when this park space is open for visitors, people can just freely cross into it from either side and then hang out without actually waiting to get through some tedious border checkpoint. So it ends up being this kind of no man's land. And then when they leave, visitors just have to exit back to their country of origin.

• 23:36Roman Mars?

  Okay, so the arch doesn't really operate as a checkpoint. But it sounds as if the entrance to each park might operate as checkpoint a little bit.

• 23:46Speaker 01

  Well, sort of, it's like you can freely walk into the park. And and there's people patrolling the park. But the real key is you should have identification with you. Because when you try to exit the park, like, they want to make sure that you're coming back into the country you're supposed to be coming back into.

• 24:04Roman Mars?

  Yeah, okay, that makes sense. That makes sense. But it's a little less rigorous than what we think of as a normal international border checkpoint.

• 24:10Speaker 01

  Oh, absolutely. Yeah, yeah.

• 24:12Roman Mars?

  Cool.

• 24:13Speaker 01

  But it started to change a little bit in this past year and a half, as you might imagine, because of the pandemic.

• 24:18Roman Mars?

  Right.

• 24:19Speaker 01

  Yeah, so each country maintains and controls its side of the park, right? And early in the pandemic, both sides kept everything open. But even after Canada decided to close its side down, Canadians have still been able to meet up with Americans by crossing into the US park along this one side.

• 24:37Roman Mars?

  Huh. Well, I can imagine a lot of people are taking advantage of that because everything else was pretty closed.

• 24:42Speaker 01

  Oh, yeah, absolutely. Like, a lot of friends and families split by the border have continued to gather here. And there have even been a ton of bi-national weddings at the park.

• 24:54Roman Mars?

  Well, that makes sense. I mean, if it's a convenient way to get together and people like get married in parks.

• 24:58Speaker 01

  Yeah, absolutely.

• 24:59Roman Mars?

  I don't know what you do after the ceremony. Do you split apart again?

• 25:03Speaker 01

  Yeah, you go your separate ways. I mean, that's that's the crazy thing, right? It's like you still have to kind of go back to your country of origin.

• 25:10Roman Mars?

  But it, you know, it's still a pretty convenient place for people to get together and celebrate.

• 25:14Speaker 01

  Yeah, it's partly that direct ease of access, but also people fully crossing over in conventional ways have faced up to a two-week quarantine and COVID testing. But they can get around all that by meeting up in this spot instead. And as you might imagine, you know, divided families who can't afford to take all that time off of work to self-isolate after a trip. I mean, this border zone loophole has been a real boon for them.

• 25:38Roman Mars?

  I'm pretty careful about all the COVID stuff. And I think that these quarantines are really, really effective. And I'm just kind of surprised that both countries just haven't shut this down entirely.

• 25:49Speaker 01

  Yeah, and you know, that's kind of the craziest part. Because legally, no matter what either country wants to do. Neither side can fully close the border because that would be an international treaty violation.

• 26:03Roman Mars?

  So this is the treaty that you mentioned dating back to the War of 1812. I mean, that that thing really has teeth, like they have to keep the border open in someplace?

• 26:12Speaker 01

  Yep, that's the idea.

• 26:13Roman Mars?

  Wow.

• 26:14Speaker 01

  And so you still have authorities policing the parks and, you know, regulating who is allowed in and where they exit. But they're not really able to just stop people from meeting up entirely.

• 26:25Roman Mars?

  Huh, that's kind of amazing. So for the sake of argument, like, what would happen if, you know, one side actually decided to like, you know, put up a wall and shut the border down? I mean, Canada was pretty proactive when it came to COVID protocols and shutting the border down. Like, what would happen if they put their wall up?

• 26:43Speaker 01

  Well, that's the thing. I was looking into this and I found this, uh, this immigration lawyer who was interviewed by the CBC. And he says that a full closure would have some pretty wild side effects. And it would depend upon like which side violates the agreement.

• 26:58Roman Mars?

  Okay.

• 26:59Speaker 01

  So he claims if Canada broke the treaty, in theory, the US could lay claim to parts of Ontario and Quebec. And if America broke it, Canada could get parts of Maine, Michigan and Wisconsin. So basically, North American geography, as we know it, is contingent on this early 1800s treaty remaining in effect.

• 27:21Roman Mars?

  This is just wild, but are people, you know, still kind of worried about meetups, you know, in this park during the pandemic anyway?

• 27:31Speaker 01

  Yeah, no, they do take it really seriously. And, and there are locals, you know, on both sides who are concerned about COVID from all these visitors, of course, which makes sense. And so a lot comes down to individual visitors and some of them play it really safe, right? They just sit on their side of the border in chairs and chat with like people from the other side across the border.

• 27:54Speaker 01

  But, you know, whatever we think or the government thinks about it in terms of health and safety, it just kind of is what it is. Neither side can actually shut it down entirely.

• 28:05Roman Mars?

  At least without, you know, trading, uh, parts of Ontario and Maine in the process.

• 28:10Speaker 01

  Right, except for that. Yeah, exactly.

• 28:17Roman Mars?

  Architecture.

• 28:19Speaker 01

  For our 500th episode, we produced a three-part series of stories on vernacular architecture, and my contribution to the set covered an ingenious regional roof design, which I learned about from a fan of the show.

• 28:38Speaker 01

  A while back, I opened an email from a 99PI listener located in Bermuda named Amy Daniels, in which she introduced me to her island's remarkable vernacular architecture. So I wrote back to her to find out more, and the next thing I knew, Amy was introducing me to a local architect.

• 28:56Speaker 02

  My name is Colin Campbell. I'm a senior architect for OBM in Bermuda. OBM is a firm that started in Bermuda over 85 years ago.

• 29:04Speaker 01

  And when I asked Colin how he and Amy knew one another.

• 29:08Speaker 02

  It's Bermuda, it's family. Amy asked her mother, and her mother, who just scratched her head, said, "Oh, I know this, though."

• 29:14Speaker 01

  So everything's two degrees of separation.

• 29:16Speaker 02

  Exactly, exactly.

• 29:18Speaker 01

  Before we got to architecture, I asked Colin to start out by just telling me about Bermuda, which, to be honest, he really sold me on.

• 29:25Speaker 02

  Bermuda is a place that, if it hadn't been made, you couldn't dream it up. It's so crazy beautiful. It's a little island. It's 22 square miles. It's just on the edge of the Gulf Stream, so we have a temperate climate as opposed to a colder North Atlantic climate.

• 29:40Speaker 01

  Colin went on to explain that the first European settlers arrived on this beautiful island back in the 1600s, and a lot of their early buildings were wood-framed. But, as we all know from The Three Little Pigs, straw and wood aren't the most robust materials.

• 29:56Speaker 02

  For almost 100 years, people did a stick-and-frame construction, and then after a couple hurricanes in 1712, 1714, a light bulb went on, and the only things left standing were stone buildings. And so the whole technology changed, and people started building with native stone.

• 30:10Speaker 01

  And so stone became a critical part of the island's vernacular. It made for robust walls, and it made use of this plentiful local material. And these stone walls were in turn topped with heavy stone roofs, which have a noticeably steep slope, a slope which serves a vital function in a hurricane. It turns out that a shallow roof can really suck during a tropical storm. While a steep roof, well, I'll just let Colin explain it.

• 30:38Speaker 02

  It doesn't suffer suction, which is the big problem in a hurricane. As the wind goes rushing over a roof, if the roof has a lower pitch, it acts as a wing and you have lift. And many buildings are torn apart, not by the wind pushing it, but the suction forces that collect on the other side of the roof. So these slightly higher pitched roofs here in Bermuda also act to create enough turbulence that they break the suction forces and they stay intact.

• 31:06Speaker 01

  So the roof pitch helps, but the most distinctive part of these rooftops visually isn't the slope. It's the way overlapping stone slats make the sides of each roof look like a bright white staircase. And this style of Bermuda roof serves a purpose related to another feature of the island's climate.

• 31:25Speaker 02

  And what this does is it slows the water down. As the water hits the roof, instead of going rushing down on a flat, plain surface, it has to go down a step.

• 31:34Speaker 01

  So while the overall pitch of the roof is steep, that's offset by this staircase shape, which keeps water from running down and off the sides too quickly.

• 31:43Speaker 02

  Almost like a little river going through pebbles and the like. So it slows the water down so you can capture the water at the gutter level and you're not losing it over the edge of the eaves.

• 31:53Speaker 01

  Catching water has been an essential function of houses in Bermuda almost since the beginning.

• 31:58Speaker 02

  And that was important because the homes did not have wells or any type of common water distribution systems. So we captured the rainwater for our potable water. And this got started in 1612 or thereabouts, just because there was insufficient water on the island available through wells and the like.

• 32:15Speaker 01

  Early settlers also came up with a clever way to top off these roofs, a coating of white lime. This bright finish helped keep houses cool by reflecting sunlight, while the lime helped purify incoming water. Of course, for this whole clever water collection system to work, it has to rain. Thankfully, the island's rainfall is generally pretty consistent.

• 32:37Speaker 02

  But not always. We've certainly seen in the last couple of years where you go two months or almost three months without any reasonable rainfall.

• 32:45Speaker 01

  To help hedge these dry spells, a typical Bermuda home can store an astonishing amount of water.

• 32:51Speaker 02

  Houses today will carry anywhere from 12,000 to 40,000 gallons of water. Every house has its own water pump and pressure system. Why that's important, especially in a hurricane-prone zone such as Bermuda, is that in the instance of a loss of power, you can all still get fresh water because every house is self-sustaining.

• 33:08Speaker 01

  This combination of self-sufficiency and the durability of local architecture helps the island bounce back incredibly fast from even major weather events.

• 33:16Speaker 02

  We don't appear to suffer the amount of damage you see in some of the other islands and the coastal parts of the United States in the post-hurricane event. In Bermuda, after a major event, the island has generally had lights on, ready to go within 24 or 36 hours.

• 33:30Speaker 01

  And that's all well and good for the residents of Bermuda. But Colin is rightfully insistent that these local solutions have global applications, too.

• 33:38Speaker 02

  The approach to conserve water and to use those resources, again, is going to be critical for the years going forward and as a strategy for communities which are going to have seasonal droughts. As we know, we're all going into a global warming condition. White roofs reflect heat. That makes sense. There should be no dark roofs in America. We should all be doing that. It's just simple science.

• 33:59Speaker 01

  I couldn't agree more. Architects would do well to study tried and tested vernacular solutions like these, and not just from Bermuda, but from around the world.

• 34:12Speaker 02

  A Bermuda roof is only white sometimes. In the reflection of the sky, there's a luminosity that happens. So the roofs are not static white. They shimmer white. And it's the interplay of light and darkness on the roofs and in the architecture that I find the most satisfying of the whole lot. To see the subtleties, you have to stand and watch it for just a little bit, and then you go, oh, that's nice. That's great. Living in an ocean environment, this little park in the middle of the Great Blue Sea is spectacular. And as a living human being, I wonder why we're here. I think in Bermuda, you can almost figure it out. I'm that close sometimes.

• 35:04Speaker 01

  More from our unofficial 99% Invisible City Expanded Audio Edition after the break.

• 35:12Roman Mars?

  Support for this episode comes from Amazon Business. When it comes to your business, procurement shouldn't be a guessing game. Whether you're running a small business or managing a large organization, Amazon Business offers smart purchasing experiences designed to meet your unique needs. Smart tech, smarter decisions. Streamline your buying process, save time and money, and gain valuable insights. Amazon Business empowers you and your team to buy with confidence. Learn more at amazonbusiness.com. Ready to give your home a style refresh? Article makes it easy to create a stylish, long-lasting home at an unbeatable price. They offer a curated selection of mid-century modern coastal and Scandi-inspired pieces that will make a perfect addition to your

• 35:56Roman Mars?

  home. All Article collections are carefully curated, focusing solely on high-quality, meaningful pieces that will stand the test of time. And with Article's 30-day satisfaction guarantee, you can shop with confidence. I'm trying to think of any of the Article furniture I haven't talked about at this point. I have couches, I have dining room sets, I have sideboards, I have, what do you call it, a media center, thing that you put a TV on, side tables, end tables, chairs. All of them are still in heavy use in my house, and all of them have held up great. Article is offering our listeners $50 off your first purchase of $100 or more. To claim, visit article.com/99 and the discount

• 36:36Roman Mars?

  will be automatically applied at checkout. That's article.com/99 for $50 off your first purchase of $100 or more.

• 36:46Speaker 03

  To the millions of small business owners out there, we appreciate you. We see your early mornings, late nights, and all the hard work in between. And with the US Bank Business Essentials Card, you don't have to go with a loan. With unlimited 2% cash back on every purchase, because we know your communities count on you to be here, there, everywhere. So yeah, we don't just appreciate you, we support you. The creditor and issuer of this card is US Bank National Association, pursuant to a license from VC USA Inc. Some restrictions may apply.

• 37:15Roman Mars?

  This fall, LL Bean is celebrating the moments people look forward to all year. The first school drop-off, the first sweater-weather day, and the first chilly evening around the fire pit. For over 100 years, LL Bean has been part of these traditions: crunching leaves in Maine-made bean boots, cheering from the sidelines in Scotch plaid flannel, and walking the dog in a rugged field coat. So grab the layers and people you love and get outside. Visit llbean.com to shop the fall collection. LL Bean: Being an Outsider.

• 37:51Roman Mars?

  At the beginning of the 99% Invisible City book, Kurt and I included two short chapters meant to set the stage for the four main ones. Dubbed conspicuous and inconspicuous, these contain stories examining aspects of cities that are either so obvious or so subtle that we tend to overlook them. First up, conspicuous.

• 38:11Speaker 01

  A few years ago, I produced a piece titled Train Set, which, you guessed it, was all about trains. And we had so much fun with that that we produced two more train-themed episodes that expanded our scope to include train cars that are conspicuously static, not on rails, but permanent, embedded fixtures of our built environment.

• 38:37Speaker 04

  Attention passengers. Food service has now begun in the dining car.

• 38:45Roman Mars?

  As a building type, diners are striking, the long and thin with chrome accents and rounded corners. Inside their narrow spaces, there's just enough room to walk through and sit down. In a built world of taller and deeper structures made with stone and brick and steel and glass, diners are kind of strange. But if you understand where they come from, all their curious design features suddenly make a lot more sense. Diners are an evolution of dining cars, you know, the ones found on trains. It's not just their name and aesthetic that traces back to railways. Many diners were prefabricated as modular units and specifically designed to be taken by truck or train to their final destination, hence the long and narrow layout.

• 39:29Roman Mars?

  Entrepreneur Jerry O'Mahony is widely credited with coming up with the diner, as it is, and building the first one in 1913. His creations evolved to have that now distinctive diner look, long and narrow, sleek and curvy with flashy chrome accents. Many vintage prefab diners came complete with counters, stools, tile floors, even restrooms, and they were just transported to the destination and they got hooked up to onsite utilities. In some cases, actual dining cars were also converted into freestanding diners, and in other cases, diners are simply made to look like classic prefabs for that nostalgic appeal. Which, by the way, totally works on me.

• 40:17Speaker 01

  Finally, as you probably know, we have an annual tradition here at 99% Invisible. At the end of the year, we gather up short mini-stories from various producers, and some of these stories are shorter than others, like this one, a sweet and simple little solo about an inconspicuous wayfinding system in New York City's Central Park.

• 40:39Roman Mars?

  One of the stories that came over the transom via Twitter this year is about the four-digit codes on the lampposts in Central Park in New York City. So each lamppost in the park has a four-digit number on it. The first two digits represent the closest cross street to the post in the 840-acre city park. So if the first two digits are 96, the post is parallel to 96th Street. The second two digits represent two things: which side the lamppost is on and its relative distance from the edge. If it is an even number, then it's on the east side of the park, so E-even, E-East, that's how I remember that. And an odd number means that that light is closer to the west side. The smaller the number, the closer it is to the edge.

• 41:26Roman Mars?

  So for example, 9605 is roughly parallel to 96th Street and it's pretty close to the West Side because it has a small odd number. But if a lamppost is numbered 9642, it's closer to the East Side than is the West Side. But because it has that high number 42, it's more towards the middle of the park. So if you ever get lost in Central Park, find a lamppost, read the embossed number, and you'll know roughly where you are. When the explanation for this code, you know, found people on the internet, a lot of people were intrigued by it. But they often wondered, well, what good is this cool wayfinding method if nobody knows about it? Well, the answer is it's not really wayfinding for us, for patrons of the park. It's really for park employees whose job it is to replace and repair those

• 42:11Roman Mars?

  lamps. Now that you know, you could like spin around with a blindfold on, set off in any direction, find a lamp and know where you are in Central Park, which is pretty cool.

• 42:30Speaker 01

  And if you love little design stories like that, you're gonna find a lot more when you page through your copy of the 99% Invisible City or listen to the audiobook narrated by our very own Roman Mars. So head to 99pi.org/book and pick up your preferred format.

• 42:48Roman Mars?

  Meanwhile, for more 99PI stories like those you heard today, be sure to check out the full episodes that Kurt mentioned, starting with Highways 101, then War, Famine, Pestilence, and Design, followed by 50, 440, or Fight, as well as 99% Vernacular and Train Sets. And finally, our annual mini-stories volumes, which you cannot miss because we're right in the middle of them right now. You can find links to all those aforementioned episodes in this week's web companion at 99pi.org.

• 43:17Speaker 01

  99% Invisible was produced this week by Roman Mars and me, Kurt Colstead, mixed by Martin Gonzalez and music by Swan Real. Roman Mars is our host, Kathy Too is our executive producer, Delaney Hall is our senior editor. The rest of the team includes Chris Berube, Jason DeLeone, Emmett Fitzgerald, Christopher Johnson, Vivian Le, LaShamadon, Joe Rosenberg, Kelly Prime, Jacob Medina Gleason, Talon, Anne Raine Stradley, and me, Kurt Colstead. The 99% Invisible logo was created by Stefan Lawrence. We are part of the SiriusXM Podcast family, now headquartered six blocks north in the Pandora Building in beautiful Uptown Oakland, California.

• 43:59Speaker 01

  You can find us on all the usual social media sites, as well as our new Discord server. There's a link to that, as well as every past episode of 99PI at 99pi.org.

• 44:17Speaker 05

  Is your heating and cooling system getting old? Did it struggle through the summer? Don't wait for it to leave you out in the cold this winter. Call James River Air and ask how you can get a new system for as little as $99 a month. That's just $3 a day. That's less than your coffee house coffee. Now through October, get up to $3,000 off with rebates and special financing. Call or visit jamesriverair.com and get back to comfort.

• 44:47Speaker 06

  Meet Craig. Craig manages the local haunted house. He's got a lot to juggle: tangled cobwebs, flickering lights, and scheduling vampires.

• 44:56Speaker 07

  Count, it's time for your break. I'll break when I'm dead. You are dead. That's like, your whole thing. Here, have a Kit Kat. Hmm, fine, 15 minutes, but no longer. Good, I'm grabbing a Kit Kat, too.

• 45:11Speaker 06

  Nobody should have to wait until they're dead to take a break. Have a break, have a Kit Kat.

• 45:17Speaker 08

  Time for a quick break to talk about McDonald's. It's the tangiest time of the year. For a limited time, head to McDonald's and get a McRib sandwich. Make it a meal by adding a medium fries and a soft drink like an ice cold Diet Dr. Pepper. So grab a McRib sandwich and embrace the tang. Save time by ordering ahead on the app at participating McDonald's for a limited time. Dr. Pepper is a registered trademark of Dr. Pepper, 7-Up Inc.