Alert Chicagoans may have already spotted the strange bundles of wires and gear on a growing number of light poles across the city. Designed to mimic the shape of weather stations, these odd additions to the streetscape look a little bit like stacks of white plastic ashtrays. But these sensors, packed with tools to collect data about environmental conditions, represent the future of urban research. Chicago’s Array of Things, an ambitious vision to collect and share city data on a micro and macro level, and potentially reshape how we formulate urban policy, is now live.

"We’ve been thinking of cities as collections of people for a long time," says Douglas Pancoast, a professor at Chicago’s School of the Art Institute who helped design the casing and sensors that form the backbone of this urban data science experiment. "I’m excited about adding physical measures of the environment to the analysis, and seeing how those two interact."

A collaborative project two years in the making, the Array of Things (AoT) was born from a partnership between the University of Chicago, Argonne National Laboratory, and the City of Chicago. The idea was to create urban "fitness trackers" that, when positioned in a grid around the city, can capture a detailed log of urban activity. The rollout of these smart city sensors now positions Chicago as a leader in urban data analysis, and offers a first-of-its kind test to see how open access to block-by-block data sets can influence urban design and city policy.

"The Array of Things is a community technology," Charlie Catlett, director of the Urban Center and Computation and Data at the University of Chicago and Argonne and the lead investigator of Array of Things, said in a statement. "It’s about creating new streams of data that help us understand and address the most critical urban challenges. Where we see an intersection of resident concerns, science interests and policymaker interest, that’s where we see opportunity for Array of Things deployment in Chicago."

The multiyear incubation process of the AoT was due, in part, to the collaborators's focus on making this system as useful a tool as possible for researchers while respecting the privacy of Chicagoans. The sensors, nodes in the larger system that measure everything from light, pollution, barometric pressure, and temperature to movement—special cameras capture the motion of people, vehicles, even animals, categorize it based on visual analysis, then destroy the image and note the activity—were continually built up over time, as designers wanted to make sure researchers could get maximum value when the system is deployed (and avoid privacy fears about some new set of cameras was watching citizens). Designed to be approachable and durable, without looking threatening, these packages now contain dozens of sensors, and can be mounted on light poles and the sides of buildings.

All the information they collect will be sent back via small Linux-based computers to a central data hub at the Argonne National Laboratory, where it will be analyzed and shared through the city's open data portal, enabling anybody to study pollution levels on the South Side, or look at traffic patterns in Lincoln Park.

The first of 50 of the nodes, built by local firm PDT, will be installed on light poles in select neighborhoods by the end of September. Each AoT sensor is modular, meaning new casing, or additional sensors, can be swapped out or added later, allowing the network to adapt in tandem with new technologies.

"We went back to researchers and asked them to identify what features would help them ask better questions," says Pancoast. "We’ll keep going back to the extended AoT community to find out how they use the data in their research practices."

Other researchers have set up city data sensors, such as Fab Lab in Barcelona, which creates Arduino based tools to measure city data, and the new LinkNYC, the new system of smart wi-fi kiosks being installed across New York City, may eventually add sensors to measure similar city data. But the AoT is unique in that it’s currently rolling out, has city backing, and will offer up its findings under an open data policy, inviting members of the scientific community, urban planners, and even involved neighbors to parse the ever-evolving data set.

While just a handful of sensors have been installed by workers in the city’s Department of Transportation—a total of 500 will be spread across Chicago by 2018 if all goes to plan—researchers already have experiment and studies lined up with participating neighborhood groups and local organizations.

In Pilsen, a traditionally Mexican-American enclave in the southwest side near industrial facilities and the Stevenson Expressway, AoT sensors are helping community groups study how air quality and pollution levels affect asthma rates. Partnerships with the Chicago Loop Alliance and Vision Zero will study traffic patterns in the Loop.The City of Chicago has expressed interest in using the sensor system to examine stormwater runoff, urban flooding, and drainage issues, and devise better and more finely tuned resilience strategies. Clusters of sensors will also be used to measure bike traffic along Milwaukee Avenue, a busy corridor on the near Northwest side, and analyze how Lake Michigan affects air quality and weather patterns.

Pancoast believes the sensors can have an impact far beyond environmental analysis. Initial data sets about, say, neighborhood pollution, can help inform local activists. Real-time traffic measurement can help improve transportation systems and city policy. Architects may even be able to utilize block-by-block data to help design more responsive and site-specific buildings.

It’s this openness and accessibility of information and data that will begin to make a city truly smart.

"It’s not just up to the city to utilize the data," he says. "The fact that it’s open means it’s not just about trained experts asking finely-tuned questions. It’s available as a resource for everyone. Putting this data out there invites introspection, action, and accountability."