Smarter Sidewalks

Brett Snyder

University of California Davis, Department of Design


How we navigate the streets has changed radically over the past decade, thanks largely to new technologies. To take just one example, smart phones have made an ever widening array of maps and information available to the public, enabling new ways of seeing and experiencing the urban landscape. iPhones allow the street to become a museum without walls, support pop-up events, and enable the creation of thematic journeys.

While our modes of navigating streets have transformed, the streetscapes themselves have remained fundamentally unchanged. We still have traffic signs, phone booths, historical plaques, and bus stops that look and operate much the way they did twenty or even fifty years ago.

Why are our streets so slow to adapt? The time is ripe to reconsider how public infrastructure could operate and how it might transform the way we navigate and experience the public realm. Could there be alternative ways to access location-based information, beyond personal digital devices—ways that help make information more widely accessible to all and lower the digital divide? Could a public media infrastructure achieve secondary aims such as reducing carbon footprints and creating more habitable cities? How can the street itself learn from the open source, mobile platforms that characterize the latest turn of the digital revolution?

In this paper, I will use a recent competition, sponsored by the City of New York, to “Reinvent Payphones” as a springboard for discussion about the future of public communications infrastructure. The competition brief prompted participants to ask: “What should the payphone be in the age of mobile?” This paper will attempt to answer this question while also asking some broader questions about public infrastructure, public space, and the future of place- based communications technologies.


For many of us, the sidewalk is simply a grey grid filling the space between the street and buildings, a bland stretch of concrete that is the ubiquitous mark of any urban landscape. But, the history of the sidewalk is a history of urban exchange. The sidewalk is the mediator between public and private zones, the buffer between different types of movement, an ephemeral and transient zone of public interaction.

The Greeks and Romans both had sidewalks, but sidewalks disappeared by medieval times, when carts and pedestrians intermingled. Sidewalks reappeared in the seventeenth and eighteenth centuries, and those of the nineteenth century were asphalt, just like the streets of today. (Loukaltou-Sideris 19) The intention of many of these early sidewalks was not that different than now: they facilitated mobility, segregated types of movement, and helped shield pedestrians against the dust from horses and carriages.

Questions over propriety emerged from the beginning: Were sidewalks and streets for locals or for outsiders? Sidewalks are a place where individual preferences continually compete with collective desires. Take, for example, this letter written from a resident of New York to the editors of The New York Times. The letter writer complains that “the badly paved and often filthy roadways are the only place to walk to and from the ferries or elevated road. Take Cortland Street any hour, great cases obstruct the sidewalks for hours…the path is ever crowded with pedestrians. Newsboys show their wares on empty cases driving the hurrying commuter to the mud. On the narrowest part of the sidewalk on Maiden Lane to air a cellar a coal hole is left open in the very center of the walk and a nine inch cage put over it. Every day someone falls over the obstruction and scores are diverted to the gutter.” This letter was published on June 4, 1903, yet none of the issues mentioned in it are foreign to contemporary residents of the city: the sidewalk is a place of congestion, negotiation, and attempted segregation, with varying degrees of success.

Furthermore, the materiality of the street and sidewalk has evolved along with citizens’ ideas about proper movement through urban spaces. Sidewalks are made from a range of materials representing both locally cheap and abundant materials, but also materials that best facilitate the speed of desired movement. Through this logic, early sidewalks were often made of better material than the street to encourage local travel while dissuading passage by outsiders. Early streets were generally supported by the adjacent owners, and their preferences regarding sidewalk use—whether it should serve travel by locals, visitors, commercial or residential use—was was often a point of contention. (Loukaltou-Sideris 20)

Issues of congestion continue to plague New York’s newest sidewalk infrastructure. Take, for example, the bike sharing system just in the process of being rolled out. In the ongoing competition for sidewalk space, the newly installed bike pedestals have met a deluge of criticism, with some residents complaining that the pedestals are simply “corridors of trash and water.” (New York Times, 2013) Never mind that the bicycle stands provide necessary infrastructure for an innovative way to navigate the city: they are still competing for precious, and hotly contested, sidewalk space.

You may have also noticed, many of these systems run off the grid, powered, for example, by photovoltaics, making it somewhat mobile and independent, at least theoretically, from dependence on other infrastructural systems.

Additionally, a change that might not be quite as visible is that the information produced by civic infrastructure is becoming increasingly open to the public. Take a look, for example at the thousands of data sets available at the website of NYC Open Data In other words, the infrastructure that surrounds us physically, also is available, in a sense, in the digital world. And there is a growing chorus, from the Smart City movement, to Hackathons, to the Occupy Movement, telling us that the ecology between these two worlds will be primary in the re-formation of the urban landscape.


So while there is technology that is embedded in the street, and data connected to this, there is another macro level of information theoretically accessible to everyone who walks around with a PDA. Thus the conscious and unconscious agents of information are us. And as we create larger, deeper data networks, their trails will increasingly impact the way the streets are inhabited.

Take the Boston bombing, for example. As events unfolded, we saw that not only were the brothers being watched by surveillance videos, but they showed up in numerous videos taken by pedestrians, videos that are all time stamped and geo-tagged. Other recent events such as Occupy Wall Street have built on the ecology between physical and digital spaces. Personal digital devices and the software and apps they support—such as Twitter and Facebook— allowed large numbers of people to strategically occupy swaths of cities far removed from each other, pushing the boundaries and regulations governing the use of urban spaces, while forming part of a larger national, and even international network or community.

And then there is the aesthetic dimension of the street that I mentioned earlier. Increasingly, a virtual network of apps, maps, and walking tours, taking their cue from the work of artistic movements like Situationists, have reinvented the way we might experience the sidewalk. A few of these include Janette Kim’s Safari 7, Janet Cardiff’s walking tours of New York, and our project Museum of the Phantom City.

Each of these projects offer alternative visions of the city. Safari-7 offers podcast tours along the number 7 train in New York featuring a range of species in relationship to the urban ecology. Janet Cardiff’s tours blur the line between fact and fiction, allowing users to peer into dreamlike scenarios all while walking through Central Park. And our project, Museum of the Phantom City, allows users to see visionary but un-built architecture on the projects’ intended site.

And the realm of urban navigation software is expanding rapidly. Currently on the iTunes store, there are hundreds of maps and guides for various cities: 385 for Philadelphia, 812 for San Francisco, 687 for Los Angeles, and 2489 for New York. Each of these offers a distinct, and technologically mediated, new way to see and experience the city.

Reinventing Payphones

What does all this have to do with payphones— something that many of us probably think of as a nearly archaic technology of the last century, something increasingly made obsolete precisely by the new technologies I’ve been discussing. In their brief for the Reinvent Payphones competition, New York City asked designers to reconsider the lowly payphone in the age of mobile.

Our response to the question posed by the brief was to reconcile two competing aims: to pack as much function into a single device as possible and to reduce the phone booth’s footprint. Our idea was to try and pack “everything”—meaning all kinds of functionality, from communication to sustainability to wayfinding— into “nothing.” That “nothing” took the form of a 6”- wide interactive strip that folds up from the sidewalk. The proposal works within the existing 5 foot x 5 foot sidewalk grid and has two main components: The first component is flush with the ground, and contains a combined sensor and display with storm runoff storage below. The second component is vertical and functions as a touch-screen, Wi-Fi hub, energy source, and a charging station, as well as providing several other performances. In short, it is a location-tethered smart-phone.

The bent form is shaped by considerations of accessibility, viewing angle, and optimal solar exposure for a photovoltaic power source. A curb-cut bleeds storm water into storage cells, dissipating it into existing soil. Sidewalk space is freed, while the invisible space below the space is put to work. The horizontal and vertical strips can exist independently or in conjunction. Under ideal conditions they are charged by PVs and also have backup systems—that is, hardwiring and batteries. Thinfrastructure is self- sustaining and can go off-grid when infrastructure fails. Hermetically sealed units can be swapped, repaired, and upgraded.

The user interface is concentrated on the front panel and includes touch screen, camera, and sound inputs. The screen vertically scrolls, accommodating a range of user heights. On the side are a credit card swipe, speaker, and charger. Built on the Android platform, existing apps are white listed by NYC. New ones would be developed by third party vendors. NYC’s urban specific apps could be accessed by an increasingly diverse range of public users: think of it as a 21st-century library without walls. While the smart sidewalk can function as a stand-alone device, it also networks, charges, and augments existing mobile devices. The 6”-wide ground strip both conveys and gathers information. Like a vehicular road counter, Smart Sidewalks passively tallies every wheelchair, child, and jogger 24/7, feeding information back to the City, to help it better address the needs of users. New York will be a sentient city.

Using a single color for the web portal— coordinating the sidewalk bands and the vertical interface—allows the city to use a variety of schemes that will differentiate neighborhoods on one day, denote flood zone locations, and celebrate a Subway Series. This offers bold, free information for all, while other specific services would be available for a time- based fee.

This massive nodal network senses wind speed, rain fall, temperature, and foot traffic with unprecedented granularity. In emergencies, Smart Sidewalks guides citizens away from danger to higher ground. As a publicly accessible database, information gathered from the streets of NY will stand to fundamentally reshape the city. With a single curb cut and a thin strip of technology NYC prepares for a changing climate, gives maximum functionality to the technological savvy, and lowers the digital divide.

Beyond our own proposal, a few common themes emerged in the six selected winners: touch screens, WiFi, emergency functions, a self-sufficient, off-the-grid energy supply. While these might not seem revolutionary, they seem to take a distinctly new approach from all other street infrastructure. The phone of tomorrow will be multifunctional and ecological. In other words, it will key in to the way the city is as well as the way it might change. One of the most interesting winners was Wind Chimes, which was designed by students from Cooper Union and the NYU ITP School. The project was fundamentally a miniature weather station that would allow micro-climatic data to be stored and shared. This is interesting because the payphone becomes as useful when it is being unused as when it is used—and it leverages the fact that it doesn’t ever move.

Future Streetscapes

So what are the lessons we might learn about sidewalks, and how might we think about them differently in the future? A place to begin, I believe, is to look at the biggest issues of our day: we use too many resources, we’re reducing biodiversity across the planet, we’re plagued by inequality that includes disparate access to technology. One could argue that the answer is right beneath our feet—and that rethinking the sidewalks might offer a key to addressing these and other issues.

Crowd sourcing information about the city and its users is the other huge area that our infrastructures could support and take advantage of. Data collection and analysis methods that, it’s important to note, are careful to respect user privacy, offer a way to potentially connect latent desires with the realities of the street. During the recent NYC Ideas Festival, projects such as the Lowline and Pluspool were voted on and resources were channeled accordingly, allowing users to have a direct and immediate impact on the public event.

And projects like David Benjamin and Natalie Jeremijenko’s Amphibious architecture set up similarly unique dialogues. This project, in the words of the designers, “is a floating installation in New York waterways that glows and blinks to provide an interface between life above water and life below.” The project establishes a network of communication among and about fish, water quality, and visitors walking by the East River. Such projects hint at a new dynamic in the city where we might not just speak with each other, but we might also find new ways of engaging previously hidden ecologies.

But more down to earth, we can certainly learn a lesson from Janette Sadik-Khan, the innovative, and sometimes controversioal, Transportation Commissioner of New York City who has chipped away at what has typically been a slow, bureaucratic process. In implementing a range of test strategies, she has truly used New York as a test bed for new ways of inhabiting the street. Often using simple means such as street graphics, movable furniture, or plantings, she has allowed the public to test and judge a wide range of prototypical strategies that have then been replicated and recalibrated.

In her essay, “Making Cities Work,” Sadik-Khan argues that “you can change a city at minimal expense and bring vibrant, healthy green spaces to communities across a city in close to real time.” There are many metrics here that suggest a radical way of rethinking our sidewalks: in other words, how can our sidewalks be leveraged as a testing ground for new ways of thinking, new types of exchanges? Just as cities like New York and San Francisco have rolled out experiments using the sidewalk as temporary lounging, dining, and park areas, we might also think of other useful experiments in street design and planning that are not only pedestrian centric, but are environmentally sensitive, ecologically minded, and that take full advantage of the functional, as well as aesthetic potentials offered by new media technologies.

Streets comprise one of the largest network systems of our urban infrastructures. They exert a powerful, and often invisible, influence on the operations, character, and experience of cities. It is high time that we start to reimagine them.

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