99% Invisible - Beyond the 99% Invisible City

Episode Date: December 30, 2025

From rogue stop signs to rooftop mini golf, discover how chaos and creativity quietly shape the urban world. Subscribe to SiriusXM Podcasts+ to listen to new episodes of 99% Invisible ad-free and a whole week early. Start a free trial now on Apple Podcasts or by visiting siriusxm.com/podcastsplus.  Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising.

This is 99% Invisible. I'm Kurt Colstead. 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 Colstead. This is 99% invisible. I'm Kurt Colstead. Okay.

No, no, no, no, no, no, no, no, no, I want you to do it again. Okay. 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, now that you have that, I want you to add like a little bit of smile in your voice. Okay. Okay. So you're going to go, this is 99% invisible.

I'm Kurt Kolstad. This is 99% invisible. I'm Kurt Kolstead. That's great. I love it. Print it. 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.

The 99% Invisible City was an instant New York Times bestseller and top the charts in the UK, Canada, and Australia. Versions of the book were also released in other countries as well, translated into languages including Spanish, Czech, Chinese, Korean, and Japanese. 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. 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. 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. That's right. Let's get started.

Infrastructure. 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. One of the things Kurt does is he checks our inbox for listeners 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. Yeah, 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. So I don't think I've ever seen that before.

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? Exactly. Why is that such a thing in the first place?

Totally. Yeah. And that got me into, of course, digging into the whole history of stop signs. Of course. Of course. That's the only way this is going to go with you. 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. Oh. Okay. So what do you have to do to earn that title? father of traffic safety. 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 in New York without cars. Right. So, of course, it's in New York without stop signs. That 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. Right, right. It wasn't very organized. More and more people were on the streets and, you know, cars started showing up. Right. And it just was included. increasingly clear that this was a mess and it was going to need some kind of regulation. And so was Eno some kind of road expert? Is that what he was working on? Well, that's the thing. Not really. He came from this family real estate business, decided it wasn't for him. It 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. Wow. So he really earned that title, the father of traffic safety. Absolutely. And once his ideas got some traction in the U.S., he began helping other cities create traffic plans. And some really recognizable designs trace back to him, like roundabouts at Piccadilly Circus in London and around the Arc to Triumph in Paris. And he was even inducted into the Legion of Honor by the French government after World War I. For traffic? Yes. Like that's what

he got that. Wow. And so was Eno the man who invented the stop sign? Well, that's the thing. I kind of filed down this rabbit hole, 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. 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 that kind of signage infrastructure. And also, you know, put this in context, right?

Stop signs back then, they weren't what we think. think of as stop signs today. Their designs varied from place to place. One of the first ones that popped up in Detroit in, I think it was 1915, had black lettering on a white background, presumably be 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. 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? 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. That's a very specific answer. Yes. Yeah. And it was a pretty good idea to make it 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. Explain more of what you mean there. 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.

Okay. So we're not talking about just associating a. rare shape with a specific meaning. There's some kind of theory behind eight having a meaning that ties to stopping. Yes. And this was a huge surprise to me. Yeah, because it sounds like nonsense. It sounds right. It sounds sort of occult almost, right? Totally. But I found this out through this New York Times Magazine article by Hillary Greenbaum and Dana Rubenstein. And I'm just going to have you read this excerpt for context that explains why the Highway Department's Association recommended different shapes for different signs. 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 in square shapes were used for informational signs end quote that is just wild it really is right 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 well yeah so i'm thinking back to like you know grade school geometry and i'm like i mean i think that there's something to that I think it's like, yeah, if you take the tangent of each point and therefore it has an infinite number of signs, but I don't think people perceive it as having infinite number of sides. I think they perceive it as having one side. Right. It's not like we look at a circle, a square, and a triangle, and we say, aha, right. Three, four, and infinite signs. It never in a million years occurred to me that there was some grand geometric theory behind U.S. 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. 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 exes and arm 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? 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 while at night. So for decades, that was the general standard. And then in the 1950s, they made red the official standard. Okay, so yellow because you can make kind of a matte yellow and it contrasts really well 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.

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 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 them red just kind of fit with the grander scheme of everything else that was going out at the time. Yeah, and it's a warning color in nature. I suppose yellow is too, but yeah, it makes sense. So how does this, you know, get us to those blue stop signs in Hawaii that Daniel found? Oh, right. And that's how we come full circle or full octagon, as it were. And it turns out the blue-painted stop. 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. 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. They have a badge. They might have a gun, but they're not actual cops. 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? Yeah, I mean, that's one of the things I think that'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. Right. Or if you saw, you know, an octagon from behind. you'll know that that's a stop sign. The other people have to stop, yeah, totally. Yeah. You know, that's a good sign. So they were onto something in Mississippi in 1923, and they figured something out.

Urbanism. 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.

That is not an association I would have made. So when I picture miniature golf courses, I kind of think of like the World War II era, you know, like sort of kitschy leisure and baby boomers and that kind of thing, not the Great Depression. 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. So did mini golf come up because like it was too expensive to maintain?

you know, big fancy golf courses or something like that? I mean, that's part of it, right? There's no way you're going to maintain these huge grounds for just a couple 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. 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. 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 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 pee-wee 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. Specifically talking about miniature pee-wee-gall. is the madness in this phrase. Absolutely insanity. That's quite the sequel to the roaring 20s.

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. Wow, I love picturing that, the people just entrepreneurally, 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? Wouldn't that happen? 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. Coursemakers could just grab whatever scraps they could find, pipes and stones and just work them into this bigger design. And there was some 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. 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 everywhere? 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 little spaces you could cram into. And so people would just head out in droves and go play mini golf. Wow. I mean, minigolf is delightful, so it doesn't surprise me all that much. But the ubiquity of it that you're describing really is striking. 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 there's apart. Things like pools and mazes and traps popped up. and eventually more kind of fancy things like fountains and forests and castles and even replicas of famous architecture like the Taj Mahal or the great well 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 has my personal favorite feature which is a trained monkey that goes after your ball so if you're not careful careful. It'll just come and snatch your ball and it's like game over. I would definitely go to that park. Oh, yeah. Yeah. I wish that one was still around today. But a lot of the elements are still around, right? 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.

Totally. It's just sort of fun to imagine New York City just being carpeted with miniature golf course, is of all things. I just, I kind of love it. Oh, I do too. I do too. Geography 99% Invisible has a recurring episode series we call MapQuests. 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.

And you have a Canadian border story for us? Oh, I do. Okay, hit me. It's about this pair of adjacent parks that are along the U.S. 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.

Wow. Well, that's a pretty bold statement for a border. Right. Which seems like antithetical to what borders are usually about. So what's the story there? 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 U.S. and the U.K. And at the end of that conflict, basically both sides signed a treaty. to leave the border between the U.S. and Canada undefended as a sign of friendship.

And so now there's this arch with this sentiment written on it, but can you truly walk through it whenever you want? 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. 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. Well, sort of, it's like you can freely walk into the park. Okay. And there's people patrolling the park. But the real key is you should have, identification with you, because when we 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. 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. Oh, absolutely. Yeah. Yeah. Cool. But it started to change a little bit on this past year and a half, as you might imagine, because of the pandemic.

Right. 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 U.S. park along this one side. Huh. Well, I could imagine a lot of people are taking advantage of that because everything else was

pretty closed. 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 binaational weddings at the park. Well, that makes sense. I mean, if it's a convenient way to get it. together and people like get married in parks. Yeah, absolutely.

I don't know what you do after the ceremony. You just split apart again? Yeah, you go your separate ways. I mean, that's the crazy thing, right? It's like you still have to kind of go back to your country of origin. But it's still a pretty convenient place for people to get together and celebrate. Yeah, it's partly that direct ease of access, but also people fully crossing over in conventional ways faced up to a two-week quarantine and COVID testing.

But they can get around all that by meeting up in this. 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. 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. 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. So this is the treaty that you mentioned dating back to the War of 1812. I mean, that thing really has teeth. Like, they have to keep the border open in some place? Yep, that's the idea. Wow. 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. Huh. That's kind of amazing. So for the sake of argument, like, what would happen if, you know, one side actually decide 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? Well, that's the thing. I was looking into this, and I found 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 which side violates the agreement. Okay. So he claims if Canada broke the treaty, in theory, the U.S. 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. 1800's treaty remaining in effect. This is just wild. But are people, you know, still kind of worried about meetups, you know, in this park during the pandemic anyway?

Yeah, no, they do take it really seriously. 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. 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. At least without, you know, trading parts of Ontario and Maine in the process. Right, except for that. Yeah, exactly. Architecture. 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.

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. My name is Colin Campbell. I'm a senior architect for OBM in Bermuda. OBM was a firm that started in Bermuda over 85 years ago. And when I asked Colin how he and Amy knew one another, it's Bermuda, his family. Amy asked her mother, and her mother who scratched her head said, oh, I know this fellow. So everything's two degrees of separation.

Exactly. Yeah. Exactly. 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. 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. 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. For almost 100 years, people did a stick-and-frame construction, and then after a couple of hurricanes in 1712, 1714, a light bulb went on, and the only thing left standing were stone buildings. And so the whole technology changed, and people started building with native stone. 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. 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. 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. 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. 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. 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. Catching water has been an essential function of houses in Bermuda almost since the beginning. And that was important because the homes did not have wells or any type of common water distribution systems. So we capture 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. Early settlers also came up with a clever way to top off these rues, 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. But not always. We've certainly seen the last couple of years where you go two months or almost three months without any reasonable rainfall. To help hedge these dry spells, a typical Bermuda home can store an astonishing amount of water. 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 still get fresh water because every house is self-sustaining. This combination of self-sufficiency and the durability of local architecture helps the island bounce back incredibly fast from even major weather events. 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-hurican event. In Bermuda, after a major event, the island has generally had lights on ready to go

within 24 or 36 hours. And that's all well and good for the residents of Bermuda. But Cullen is rightfully insistent that these local solutions have global applications, too. The approach to conserve water and to use those resources, again, is going to be critical for the years going forward 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. 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.

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 for a little bit, and then you go, oh, 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, one wonders why we're here. I think in Bermuda you can almost figure it out. I'm that close sometimes. More from our unofficial, 99% Invisible City expanded audio edition after the break. 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. 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. Attention passengers. Food service has now begun. in the dining car. 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 entrepreneur jerry o mahoney is widely credited with coming up with the diner as it is and building the first one in nineteen thirteen 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 on-site 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. Finally, as you probably know, we have an annual tradition here at 99% Invisible. At the end of the year, we gather up short, many 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 way-finding system in New York City's Central Park.

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 lamp post 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-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. 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 lamp post is numbered 9642, it's closer to the east side than it is the west side. But because it has that high number of 42, it's more towards the middle of the park.

So if you ever get lost in Central Park, find a lamp post, read the emboss number, and you'll know roughly where you are. When the explanation for this code found people on the internet, a lot of people were intrigued by it, but they often wondered, 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 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. And if you love little design stories like that, you're going to find a little design stories like that, you're going to 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 slash book and pick up your preferred format.

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, Pestulence, and Design, followed by 5440 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 buy links to all those aforementioned episodes

in this week's web companion at 99PI.org. 99% Invisible was produced this week by Roman Mars and me, Kurt Colstead, mixed by Martine 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 Barubei, Jason DeLeon, and Fitzgerald, Christopher Johnson, Vivian Lay, Lasha Madan, Joe Rosenberg, Kelly Prime, Jacob Medina Gleason,

Tallinn, and Rain Stradley, and me, Kirk Colstead. The 99% Invisible Logo was created by Stephen Lawrence. We are part of the Serious X-M podcast family, now headquartered six blocks north in the Pandora building in beautiful uptown, Oakland, California. 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.