The free Wi-Fi kiosks that Alphabet’s urban innovation division Sidewalk Labs is selling — similar to those already on the streets of New York — will come with eyes, ears and a host of environmental, air and digital sensors to give the tech giant an unprecedented snapshot of urban life, according to documents obtained by Recode.

The documents, which formed part of Sidewalk Labs’ pitch to cities participating in the U.S. Department of Transportation’s Smart City Challenge, show that Alphabet — Google’s parent company — wants to monitor pedestrian, bike and car traffic, track passing wireless devices, listen to street noise and use the kiosks’ built-in video cameras to identify abandoned packages. Each kiosk will also generate an estimated $30,000 a year for the company from digital advertising.

"The Kiosk sensor platform will help address complex issues where real-time ground truth is needed: Understanding and measuring traffic congestion, identifying dangerous situations like gas leaks, monitoring air quality, and identifying quality of life issues like idling trucks," says one promotional flyer. Recode obtained the documents under public records laws.

Sidewalk Labs is led by Daniel Doctoroff, who was New York City’s deputy mayor for economic development and rebuilding under Michael Bloomberg, and was also the former CEO of Bloomberg LP. The firm describes itself as a "new type of company that works with cities to build products addressing big urban problems" and one that’s "building a platform" to "accelerate innovation" in cities.

Around two hundred kiosks, without sensor suites, have already been installed in New York City by LinkNYC. This is a consortium that includes Intersection, a high-tech advertising consultancy owned by yet another consortium, led by Sidewalk Labs.

Each 9.5-foot-high Link kiosk offers a range of free services, including U.S. phone calls, gigabit Wi-Fi access, USB charging ports and transport directions. The kiosks have a keypad, a touchscreen tablet for browsing, a dedicated 911 button for emergencies and are ADA compliant. Sidewalk’s documents quote market research that found 90 percent of New Yorkers believe the kiosks are a "positive initiative for the city."

But this is only the start of what Sidewalk Labs has planned. Sidewalk offered the Columbus, Ohio, winner of the Smart City Challenge up to 100 kiosks in four of its neighborhoods. "Each Kiosk," promises Sidewalk, "includes data analytics [that would allow Columbus to] better understand the urban environment via environmental sensors and machine learning algorithms that integrate numerous data sources."

Sidewalk has been working with the U.S. Department of Energy’s Argonne National Lab to test dozens of different sensors, grouped into four areas. "Environmental" sensors will measure humidity, atmospheric pressure and the temperature of the air, street and sidewalk. "Air Pollutant" devices would track particulates, ozone, carbon monoxide, nitrogen and sulfur dioxides, and more.

The kiosks would also follow "Natural and Manmade Behavior" by measuring vibrations from vehicles, magnetic fields, sound levels, and infrared, visible and ultraviolet light. Finally, "City Activity" monitoring would include collecting anonymized sightings of wireless devices (probably via Wi-Fi) and a video camera watching the kiosk’s surroundings. Each city could choose which sensors it wanted to install in its kiosks.

"We believe making aggregated views of this data public will contribute to the expanding startup community developing innovative products for shared public spaces," says the document. Sidewalk itself plans to use the wireless device data and video monitoring of passing people and vehicles to calculate average roadway speeds and travel times. Alphabet would then feed this data back into its Google Maps navigation app.

Sidewalk suggests that the video sensors might spot "abandoned packages or objects," raising the possibility of the technology being used to foil terrorist incidents. More mundanely, the company says the camera could also detect clogged drains and standing water on roadways.

"It is a win-win solution," says Alexei Pozdnoukhov, director of the Smart Cities Research Center at the University of California at Berkeley. "Cities get environmental sensing to meet public health regulations and figure out the ‘livability’ of streets, and companies get ... a playground for building new services."

Sidewalk’s documents suggest that future developments for the kiosks might include small cells to improve cellphone reception or integrating them into Internet of Things networks.

Sidewalk Labs says that all data would be anonymized, with any personally identifiable information being encrypted and routinely deleted after being aggregated. No raw data would be sold or shared with any third party, including Alphabet and Google. Sidewalk also insists: "We will never collect or use PII gathered through our sensor platform."

Following a complaint by the New York Civil Liberties Union in March about LinkNYC’s privacy policy, the company has confirmed to Recode that its kiosks’ cameras have never actually been turned on.

The documents obtained by Recode also spell out the financial benefits of installing Sidewalk’s kiosks. While the kiosks themselves would be supplied free of charge, cities would be responsible for the cost of installing them ($12,900 each) and connecting the gigabit internet optical fiber ($15,000). Cities would also contribute $5,000 per kiosk to a "warranty and hardware refresh fund," presumably to allow for repairs and upgrades.

Along with these one-off costs, Sidewalk predicts that each kiosk would run up $1,440 in maintenance fees, $2,400 in power bills and a hefty $8,400 in fiber charges annually. The total first-year expenses for a city installing 100 kiosks would be more than $4.5 million.

If a city chooses to upgrade its kiosks to include advertising, however, the numbers look far more attractive. For a start, Sidewalk would finance the $23,000 cost per unit of installing twin 55-inch screens. It would also sell and place the ads, raising an estimated $60,000 per year from each kiosk. Sidewalk would keep half of this, giving the city annual revenues of $3 million from its fleet. If Sidewalk’s predictions are correct, the kiosks would pay for themselves in less than two years.

Even so, Sidewalk appears to be facing a tough sell. Rory McGuiness of Columbus’s Department of Development says, "We had meetings with Alphabet about the kiosks. There are some intriguing things about them, but there are also other companies that also have some very interesting kiosks. We have not signed any agreements yet."

Whether it is Sidewalk’s kiosks or those of a rival that end up on the street corners of Columbus, two things seems certain. Urban Wi-Fi is about to get a whole lot faster and easier, and our cities a whole lot more connected.

Mark Harris is an investigative technology reporter based in Seattle. In 2014, he was Knight Science Journalism Fellow at MIT, and in 2015 he won the AAS Kavli Science Journalism Gold Award. Reach him @meharris.