The 99% Invisible City

A Field Guide to the Hidden World of Everyday Design

Roman Mars, Kurt Kohlstedt

• Publisher: Mariner Books
• Year: 2020
• Print ISBN: 9780358126607
• eBook ISBN: 9780358125020
• Topic: Design
• Subtopic: Architecture General

A NEW YORK TIMES, WASHINGTON POST, USA TODAY, AND PUBLISHERS WEEKLY BESTSELLER

“[A] diverse and enlightening book . . . The 99% Invisible City is altogether fresh and imaginative when it comes to thinking about urban spaces.”
—The New York Times Book Review

“Here is a field guide, a boon, a bible, for the urban curious. Your city’s secret anatomy laid bare—a hundred things you look at but don’t see, see but don’t know. Each entry is a compact, surprising story, a thought piece, an invitation to marvel. Together, they are almost transformative. To know why things are as they are adds a satisfying richness to daily existence. This book is terrific, just terrific.”
—Mary Roach, New York Times bestselling author of Stiff, Grunt, and Gulp

“The 99% Invisible City brings into view the fascinating but often unnoticed worlds we walk and drive through every day, and to read it is to feel newly alive and aware of your place in the world. This book made me laugh, and it made me cry, and it reminded me to always read the plaque.”
—John Green, New York Times bestselling author of The Fault in Our Stars and Turtles All The Way Down

A beautifully designed guidebook to the unnoticed yet essential elements of our cities, from the creators of the wildly popular 99% Invisible podcast 

Have you ever wondered what those bright, squiggly graffiti marks on the sidewalk mean?

Or stopped to consider why you don't see metal fire escapes on new buildings?

Or pondered the story behind those dancing inflatable figures in car dealerships?

99% Invisible is a big-ideas podcast about small-seeming things, revealing stories baked into the buildings we inhabit, the streets we drive, and the sidewalks we traverse. The show celebrates design and architecture in all of its functional glory and accidental absurdity, with intriguing tales of both designers and the people impacted by their designs.

Now, in The 99% Invisible City: A Field Guide to Hidden World of Everyday Design, host Roman Mars and coauthor Kurt Kohlstedt zoom in on the various elements that make our cities work, exploring the origins and other fascinating stories behind everything from power grids and fire escapes to drinking fountains and street signs. With deeply researched entries and beautiful line drawings throughout, The 99% Invisible City will captivate devoted fans of the show and anyone curious about design, urban environments, and the unsung marvels of the world around them.

Chapter 1

Inconspicuous

 

There is a hidden world of design all around you if you look closely enough, but the cacophony of visual noise in our cities can make it hard to notice key details. There are street markings that protect you from being blown to bits, tiny safes affixed to building exteriors that can help save occupants in a fire, and ornamental flourishes that may seem like mere decoration but actually work to hold entire brick buildings together. Amid all of this, there are also myriad incremental odds and ends that simply accumulate through people forever reshaping a city to fit their needs. Decoding these more subtle aspects of the cityscape can also help you gain insight into the people who make cities what they are, most of whom are just trying to live their lives, but some of whom are actively trying to save yours.

Sidewalk markers, a breakaway post, and emergency access box

Ubiquitous

Once you start to see them, you’ll never understand how you hadn’t noticed them before. On any given city street, there are design details scattered everywhere that are meant to establish boundaries or protect you on an everyday basis and in cases of emergency. Even obscure notations created and used by specialists contain layers of information written onto the built world that can be read by anyone who knows how to decipher them.

Official Graffiti

Utility Codes

Careless or uninformed digging around cables and pipes can cause everything from major utility outages to gas leaks—or, as in the case of a 1976 incident in California, a gigantic explosion that leveled half a city block. One fateful day in June of that year, workers were excavating a stretch of Venice Boulevard in Los Angeles when someone accidentally cut into a hidden petroleum pipeline. The pipe ruptured, and pressurized gas ignited into a fireball that engulfed passing cars and adjacent businesses. More than two dozen people were killed or injured as a result of this error. This wasn’t the first or last tragedy of its kind, but the enormity of this particular disaster helped catalyze the codification of critical color-coded utility markings that are so omnipresent today. If you are in a US city, look down and you will see colorful official street graffiti everywhere; these markings are a guide to the networks of pipes, wires, and tubes crisscrossing below you.

The Los Angeles explosion spurred the creation of DigAlert, a nonprofit designed to help prevent future such tragedies in Southern California. Today, excavators in the region are required to mark out their work areas with white paint, chalk, or flags, and reach out to DigAlert; the organization then identifies and contacts companies with utilities running through the site so their technicians can go out and mark off potential hazards. Locators sent out by these companies can employ cable avoidance tools to establish or confirm the positions and depths of things below the surface. Ground-penetrating radar and devices to detect metals or magnetic fields help pinpoint concrete pipes, plastic tubes, and metal cables. Potential subsurface hazards are then highlighted using standardized colored-coded markings.

Over the decades, services similar to DigAlert have formed across the United States. To simplify things, the FCC designated 811 as a federal phone number in 2005 to connect excavators with these organizations. In general, anyone excavating on public property is required to contact a regional alert organization before proceeding, though private property owners are encouraged to reach out as well. According to a recent DIRT (Damage Information Reporting Tool) report, tens of thousands of accidents could be avoided each year if everyone called when planning to dig, drill, blast, or trench.

For clarity and consistency, US utility companies rely on Uniform Color Codes developed by the American Public Works Association when mapping out subterranean utilities on surfaces above. On city streets today, you can see the spectrum of safety colors that have been formalized and revised over the decades by the American National Standards Institute:

• RED: electric power lines, cables, and conduit
• ORANGE: telecommunications, alarm and signal lines
• YELLOW: gaseous or combustive materials including natural gas, oil, petroleum, and steam
• GREEN: sewers and drain lines
• BLUE: potable water
• PURPLE: reclaimed water, irrigation, or slurry lines
• PINK: temporary markings, unidentified facilities, or known unknowns
• WHITE: proposed excavation areas, limits, or routes

While the use of different colors provides general information about what’s below, notations including lines, arrows, and numbers are also needed to keep track of details about the locations, widths, and depths of specific hazards. Here, too, standards are helpful, and there are organizations dedicated to helping coordinate and disseminate these. Among other functions, the nonprofit Common Ground Alliance maintains an exhaustive best practices guide for “underground safety and damage prevention.” Documents like this one also provide useful explanations and diagrams for curious urbanists looking to decode street markings.

Some enthusiasts take things a step further and create more expansive guides. Artist Ingrid Burrington’s book, Networks of New York, contains more than one hundred pages on just one color category of utility in one city: the orange that designates network infrastructure in the Big Apple. Her volume dives deeply into the history of competing telecoms, but it also lays out practical examples for identification like an arrow flanked by the letters F and O, which together indicate the path of a fiber optic line directly below a stretch of pavement. In the wild, such markings are sometimes accompanied by numbers indicating depths, names identifying associated utility companies, and abbreviations referring to the types of materials in play, such as PLA for plastic pipes.

Different countries have their own national, regional, and local conventions, too, which can be more or less official. In a BBC News article, journalist Laurence Cawley scratches the surface of London’s underground utilities with some local examples, including ones that illustrate how intuitive certain codes can be. A number next to a D often indicates depth, for instance. For electrical lines, H/V means high voltage, L/Fdenotes low voltage, and S/L stands for street lights. For gas lines, HP refers to high pressure, MP to medium pressure, and LP to low pressure. Some markings are harder to understand at first glance, like a looping infinity symbol used to indicate the beginning or end of a proposed project area—a counterintuitive use of a character normally applied to things without beginnings or ends. Biodegradable paints are typically employed to create the variously colored letters and symbols sprayed by specialists onto the streets and sidewalks of our cities. These odd hieroglyphics are then either erased in the course of excavations or simply left to fade over time, slowly making room for newer, more vibrant squiggles when the next project rolls around. While they last, though, such markings provide essential information to diggers as well as ephemeral windows for the rest of us into the complex systems running right beneath our feet.

Initialed Impressions

Sidewalk Markings

As the country’s original capital and the backdrop for many key moments of American history, the city of Philadelphia is lousy with important era-defining monuments and plaques, whose grandeur can make subtler and less dramatic markers easy to miss. Amid the many statues standing in squares and tablets affixed to buildings are a series of enigmatic plaques embedded in sidewalks. The etched or embossed messages on these metal plaques read like abstract spatial koans or urban poems advising pedestrians that “Space within building lines not dedicated” or “Property behind this plaque not dedicated.”

In property law, dedicating means giving over to another party—the public, for example. The wording on these plaques varies, but the basic message of these so-called easement markers is the same: you pedestrians are welcome to walk here for now, but just a heads-up—this is actually private property. To define such areas, long thin rectangular plaques are often arrayed to form a dashed demarcation line along the boundary of the property while right-angled variations are used to define the corners.

In a 2016 PlanPhilly article, reporter Jim Saksa explains that “the plaques are used when the property lines don’t align with the building’s physical dimensions or the dimensions of any sort of fencing, landscaping or other improvements that would clearly mark a boundary between the public right-of-way and private property.” In other words, a passerby might assume a property line ends at a fence or hedge or the edge of a building when the actual property line might run through a sidewalk instead.

Easement laws can give people limited rights to cross other people’s land but can also allow for different forms of adverse possession. As Saksa explains the concept, if someone uses a piece of property “blatantly, consistently and exclusively for a long, statutorily set amount of time—21 years in Pennsylvania—then they own it.” In the case of these prescriptive easements in Philadelphia: if private owners fail to explicitly mark out their territory, someone could eventually argue they have forfeited ownership. That’s why you’ll see these markers embedded in sidewalks both there and in other cities. The plaques ensure that the public knows that this particular patch of sidewalk belongs to the property owner even if they allow the public to walk on it for now.

Such plaques only scratch the proverbial surface of the sidewalk etchings that comprise a cityscape. There are, of course, the ubiquitous informal markings made less than legally by ordinary citizens, like so-and-so + so-and-so with a heart around it scratched into drying concrete sidewalks. But there are formal marks, too, and not just for easements. Among the semi-permanent declarations of love, you’ll find elegant signatures in many cities that were left by the construction companies that laid the sidewalk.

In California’s Bay Area, sidewalks in cities like Oakland feature stamps or plaques dating back t...

Table of contents

• Title Page
• Contents
• The 99% Invisible Field Guide to the Cover
• Dedication
• Copyright
• Introduction
• Chapter 1: Inconspicuous
• Ubiquitous
• Camouflage
• Accretions
• Chapter 2: Conspicuous
• Identity
• Safety
• Signage
• Chapter 3: Infrastructure
• Civic
• Water
• Technology
• Roadways
• Public
• Chapter 4: Architecture
• Liminal
• Materials
• Regulations
• Towers
• Foundations
• Heritage
• Chapter 5: Geography
• Delineations
• Configurations
• Designations
• Landscapes
• Synanthropes
• Chapter 6: Urbanism
• Hostilities
• Interventions
• Catalysts
• Outro
• Acknowledgments
• Bibliography
• Index
• About the Authors
• Connect on Social Media