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High-Tech Sensors Could Change The Game For Developers And Community Groups

Computer scientists Charlie Catlett and Rajesh Sankaran were chatting in Chicago's Berghoff Cafe in 2012 when they began sketching on napkins an idea for high-tech data sensors that would sit atop traffic lights and absorb information on everything that happens in a city: air pollution, pedestrian traffic, automobile use and noise. 

Those quick scrawls eventually led to Chicago becoming the testing ground for an experiment that could change commercial development. After getting buy-in from city officials, as well as a $3.1M grant from the National Science Foundation, the researchers eventually installed about 130 of the sensors, dubbed the Array of Things, which was developed at Argonne National Laboratory and the University of Chicago.

An Array of Things device perched above Damen Avenue and the Kennedy Expressway.

For several years, the nodes have gone mostly unnoticed while recording data with miniature cameras, microphones, light sensors and other instruments. Designed to live about two years, some are now almost six years old and have outlived their usefulness, according to Catlett, now senior research scientist at the University of Illinois Discovery Partners Institute and director of the AoT project.

But Argonne has now joined with Northwestern University, Discovery Partners Institute, the University of Chicago and other teams and gone national with its next-generation sensors, called Sage. These sensors offer more analytic power, as well as higher-resolution cameras and sound detectors. In addition to Chicago, urban areas in Texas will host Sage devices. Devices will also be planted across California and other Western states to detect wildfires.

“The Array of Things was like the first iPhone, and Sage is like the iPhone 13,” Catlett said. “We can do much more detailed analysis.”

The network will be available to community groups, developers, planning agencies and others who want to understand the built environment.

AoT had limited commercial uses, but Sage may be different, Catlett said. AoT was a scientific research experiment, testing whether scientists and planners could design, install and operate such a data collection system, including how to protect the devices from water or dust damage. Catlett said Sage is tested and ready to measure air quality, record weather, track pedestrians and even count migratory birds, among many other measurements.

Easy-to-use software will make sure the data is open and available to everyone.

“You don’t have to be trained as a data scientist,” Catlett said.

One lesson learned since Chicago Department of Transportation workers mounted in 2016 the first AoT device on a traffic light in the Pilsen neighborhood was that some measurements, such as noise, pollution and temperature, are simple and are better handled by small, cheap gadgets. Each AoT costs about $2,500, too expensive to blanket the city, leaving huge gaps where air quality couldn’t be measured.

To bolster Sage, the project, which has a $9M grant from the National Science Foundation, will also attach perhaps hundreds of smaller sensors that track pollution and noise to structures such as bus shelters throughout the city.

“We’ll probably need several hundred, if not a thousand, for a city like Chicago,” Catlett said.

Workers will start swapping out the AoT devices with Sage this year, and there will probably be several dozen by spring or early summer, he added.

The Sage project could be a game-changer for development, according to Environmental Law & Policy Center Community Science Organizer Tiffany Werner.

Noise, pollution and vibrations from construction sites are frequent sources of friction between communities and developers, especially in residential neighborhoods, she said. But often neither side has access to accurate, up-to-date information, so these battles frequently happen in the dark.

A fight over air quality, for example, erupted between local community organizations on Chicago’s Southeast Side and Reserve Management Group, a recycling firm at 11600 South Burley Ave., after it bought General Iron Industry’s aging metal shredding operation in affluent Lincoln Park on the North Side and announced plans in 2020 to shift it to the majority-Latino and Black neighborhood.

General Iron's North Side facility shortly before its December 2020 shutdown.

Community groups have complained the operation will further pollute a neighborhood that already has the city’s worst air quality. RMG denies this, touting its advanced pollution control technology. The city delayed granting the company a permit after federal officials asked for more analysis on possible health impacts.

One problem, however, is that whenever an agency, whether from the city or the federal government, attempts to measure Southeast Side air quality, it is typically a snapshot in time. Measurements on one day may not match those done on another, Werner said. There is also no data on how air quality did or didn’t improve in Lincoln Park after General Iron was shuttered there on Dec. 31, 2020.

That doesn’t have to be the case in the future.

“Systems like the Array of Things and Sage allow constant monitoring, so everyone can see trends happening over time,” Werner said. “Our communities really want to use this data.”

Catlett said Discovery Partners Institute could partner with commercial developers worried about how construction will impact surrounding neighborhoods.

“What you could do, even with the lower-cost devices we have, is put one at every corner of a construction site,” he said.

That way, whenever neighbors or a local alderman raised questions about noise, dust or vibrations, answers would be swiftly available, hopefully heading off controversy before it even starts.

“If I was a developer, I would post the data every day,” Catlett said.

Slipstream Executive Vice President Karen Weigert, who as chief sustainability officer of the city of Chicago from 2011 to 2016 helped get AoT started, said outdoor high-tech data collection efforts are useful for developers and landlords beyond the end of construction.

“Many companies have tremendous amounts of data about the insides of their buildings,” she said.

But they know little about how the same buildings impact the surrounding streets and sidewalks, data that Sage can provide and help improve urban planning and design.

It is a layer of data that we now have the technology to produce, and Chicago shouldn’t be the only city to tap into it, she added.

“Hopefully, other cities will learn from ours.”