Sam Slover and six colleagues think New Yorkers might someday want to call one of the city's payphones even when no one is around to pick up.

On Jan. 27, Slover, a student in New York University's Interactive Telecommunication Program, and his six colleagues previewed Street Beacon, a reimagined payphone. In their envisioning, each phone is also a listening post in the connected city. Users can call up a phone in any neighborhood — over the Internet, rather than by landline — and check up on the health of that city block. Each street beacon would record noise levels and air quality for subscribers to check online — or to walk up and review on a touchscreen display. Local businesses would also pay to place digital advertising through that node, generating revenue for the city.

The team was one group of several at ITP that weekend for an event to come up with ideas that might become part of Reinvent Payphones, a city-sponsored initiative to rethink what to do with the nondescript boxes scattered across the five boroughs. New York has 11,000 payphones that generate $17.7 million in revenue annually — but the world is increasingly going wireless and $16 million of that revenue is from advertising. Rather than spend money tearing out infrastructure that doubles as a backup communications network in case of emergency, New York announced last year that it would come up with new ways to adapt payphones for the digital world. Cities have long found ways to repurpose old scraps of infrastructure. Also in New York, for example, a disused spur of elevated rail line was transformed from an eyesore into the High Line, a trend-setting public park.

As leading city governments across the country consider how to approach the Internet age, they're taking this concept to a new frontier by thinking of new ways to turn old standbys into digital infrastructure. Payphones are just the latest piece of the old city that officials are hoping to forge into part of the new digital public way, a trend that is also sweeping city hall in Boston and Chicago.

The High Line in New York was converted from abandoned and wild (foreground) to an elevated park (background). Composite illustration

"There's this term called 'adaptive reuse,' and that's been around for some time," says Dan Latorre, vice president of digital placemaking at the nonprofit planning, design and educational organization Project for Public Spaces.

"When there's great economic challenge, it sparks the need to be innovative and resourceful," he says.

For New York City officials, payphones are a prime untapped resource.

"We have 13 payphone franchises that expire in October of 2014," says Stanley Shor, assistant commissioner at the New York City Department of Information Technology and Telecommunication, which manages the city's payphones. "So we have until then to figure out what we want to do next."

The city is now collecting information to see what kind of ideas are on the table, and might put out an official request for procurement later this year. The city is also testing free Wi-Fi at 13 payphones through the city, and has installed experimental touch screens on others.

Both pilots will report back to DoITT to help inform the official request for procurement. And the city's encouraging potential vendors to think big.

"There are no constraints," Rachel Haot, the city's chief digital officer, said in an interview. "It doesn't even have to look like a payphone."

Boston's red fire alarm boxes, invented near the city in the mid-19th century, are too iconic to completely change their design. But Mayor Thomas Menino’s office is looking to use the 2,200 boxes in a new way on the premise that there's got to be a new use for infrastructure that costs the city $2 million in annual upkeep to maintain.

Deputy Fire Commissioner Justin Brown was at a city meeting which included a discussion of digital infrastructure when he realized he was sitting on an untapped asset.

“It dawned on me, wait a minute, we’ve got this fixed infrastructure all over the city and we don’t know what to use it for,” he said.

Boston’s request for information, which is open through February 22, says the city is searching for a proposal that “could include adding a digital kiosk to the fireboxes so pedestrians could get and give information about the city; it could be adding a wireless hotspot or a phone charger to them to help people stay connected as they travel through Boston; it could be adding sensors that monitor air quality, noise pollution,traffic or light levels; it might display urgent or geographically‐based public messages: or a range of other things.”

Payphone locations in New York City. Illustration: Nick Judd / techPresident | Map data: NYC DoITT

But "fixed infrastructure" takes on a whole different meaning in Chicago. Introduced last year, the Chicago Broadband Challenge asked members of the public to share their ideas on how to get super-high-speed fiber-optic Internet connections into the city, expand broadband access into Chicago's poorer neighborhoods, and establish free WiFi in public spaces.

“We really play up the mostly unintended benefits of legacy infrastructure on next generation infrastructure,” says Chicago’s Chief Technology Officer John Tolva, “it absolutely helps.”

Chicago's old-school industrial legacy might help city officials create a new digital future. Inside the city's central business district, the Loop, Tolva says, a freight tunnel travels under every single street. As Upton Sinclair published "The Jungle," his dystopian look at industrial-era Chicago, in 1906, those tunnels were already hauling freight. But their remnants could form the backbone of a new fiber-optic network.

"Sixty percent of the cost of laying fiber is ripping up the street and paying to repave it," Tolva said. What's left of that rail tunnel network leaves enough elbow room for workers to run cable without tearing up the street above.

While "totally unsexy," he added, sewers or even alleyways could provide the necessary right-of-way to lay new groundwork for a more wired city.

For now, these are just big ideas. Chicago's "broadband challenge" ended its request for information phase in November with two dozen respondents, including telecom giants like the backbone Internet provider Level 3 and the networking device manufacturer Cisco. New York City is still in the "just-listening" phase.

But the main idea — that engineers could hack dated infrastructure for the city, transforming fire alarm boxes or freight tunnels into a platform for future innovations — that's sunk in.

"When something is already there," says Shor, from New York City, "it's easier to reinvent than build something new."