Chicago Deploys Nodes to Create Open, Free City-Wide Data


The Chicago Array of Things project is a fascinating IoT experiment, bringing scientists, architects, researchers, and students together towards exploring what federal governments must do to help cities navigate the next 50 to 80 years. The ultimate goal of the project is to provide open, free data about the performance, environment, and activities of the city to residents, policy makers, scientists, and industry. The experiment relies on the installation of sci-fi-esque nodes on city light posts which contain sensors that measure temperature, barometric pressure, light, vibration, carbon monoxide, nitrogen dioxide, sulfur dioxide, ozone, ambient sound intensity, pedestrian and vehicular traffic, and surface temperature. Since 2016, nodes have been deployed throughout Chicago’s downtown core with plans to deploy more in 2018. 

Inside the Nodes

The nodes are a joint project by Argonne and researchers from 30+ universities. The inner board is designed by Argonne and the interior is comprised of off the shelf sensors such as AirSense Board (Intel), Camera, ChemSense Board, WagMan Board + ODROID (Amlogic quad ARM A7), ODROID (Samsung Exynos5422, A15 &A7), LightSense Board, and IR Temp.The platform built by Argonne is called Waggle. The nodes contain the Waggle Manager which manages resilience. The sensors themselves are kept safe inside of upside down metal bowls, designed by PDT, which have small slits allowing ambient light and air through to the sensor boards. As a result of its design, direct sunlight and rain cannot hit the boards. The structure also protects against ice and and human mischief. Thankfully, if a node were to become damaged, a replacement only runs in the field of 1-2 thousand dollars instead of in the tens of thousands. As sensors shrink in size and become more affordable, the Array of Things is spreading to other cities as pilot projects. Indeed, as of 2016, over 60 cities and universities from around the world expressed interest in testing the Array of Things. Seattle, Portland, Denver, Chattanooga, Paris, Washington , Bristol, Newcastle, Delhi, Hong Kong, and Paris are among forward-thinking cities ready to make the leap into IoT.


Array of Things Node

Nodes relay information to the Argonne server.


What can be done with the collected data?


Data collected by nodes is made available to scientists, policymakers, and businesses on a portal called The online interface tool makes splitting data into workable chunks a simple and rewarding task. Users select a set of time-series data, a geographic space such as a region or city block, and a filter for the type of data desired such as violent crime, air quality levels, pedestrian traffic, etc. For citizens and students, another portal called provides users with the option to build applications from the Argonne server. This data is being used in Chicago schools to involve youth in the future of their urban environment.

“Chicago and cities around the world want to make sure that their students receive education and experience in the technical skills that will be in demand in tomorrow’s economy,” said Charlie Catlett, CI Senior Fellow and UrbanCCD Director. “We think that Array of Things provides a perfect platform for students to learn about the basics of computer science in the context of engagement with their surroundings.”


Classroom Engagement, Urban Planning, and Third-Party Apps


Students from Chicago schools have already made use of sensor data from both nodes and student-built sensors around their schools, monitoring dust and methane, foot traffic, and humidity. The findings spark ideas for ways in which students can become involved in bettering their schools and communities. The goal of “Lane of Things” – the student branch of Array of Things, is to have students give back to their community with original research.

For scientists, urban planners, and environmental experts, the goals of the Array of Things project are considerably more rigorous. Scientists hope to use air quality data, socio-economic data, and crime statistics among other verticals to create ‘neighborhood health indices’ and city coordinators plan to use city-wide data to predict rates of EMS calls and their contributing factors, optimize routes for snow ploughs, garbage trucks, ambulances, fire, and police vehicles, estimate the micro GNP of neighborhoods and sub-neighborhoods, predict spikes or falls in the neighborhood health index, and create unique building IDs across datasets.


Air Quality Sensors

Air Quality within Chicago


City-wide building indices have already been realized in Boston. Boston’s fire department relies on a database of real-time building information which informs firefighters as to the location of hydrants, building exits, stairwells, rooms, construction materials, and even personnel within compromised structures. Armed with data, fire trucks arrive on scenes within moments due to route optimization.

Corporations will be able to access Array Data to offer quality of life enhancing services such as real-time air quality maps which may indicate ‘green’ routes for pedestrians walking on hot and smoggy days. Apps may direct pedestrians to green and blue routes as air quality beside city parks and waterfronts is remarkably better than that of inner streets. When you compare air pollution within different regions of Chicago, 20% of children have asthma in red areas vs 10% in green areas. Scientists will be able to look into how urban development affects heat islands and air quality so as to avoid regions which contribute to ill health and disease. Other applications may access foot traffic data to lead users along a low-noise or low traffic route.






Sensor Data: Mitigating Inequalities


Throughout Chicago and pilot cities, sensor data will inform policies which seek to mitigate inequalities in urban areas. By determining why life expectancy in some regions is lower, city planning may be able to rectify air quality or transportation issues which are contributing to poor quality of life. Already, social scientists have found striking correlations on which relate life expectancy, asthma, urban heat islands, and transit time to loop to socio-economic disparities and life expectancy rates. In some neighborhoods, there can be a 20 year difference in life expectancy based on these micro-factors. Array of Things nodes will be able to report on typical 311 issues such as standing water within neighborhoods, traffic and pedestrian flow, and time-to-clear for traffic accidents.

“One of the things we’re hoping to be able to help city departments with is where we have poor street conditions,” says Brenna Berman, the city’s chief information officer. “When it rains, we know we have flooding in Chicago, and we certainly get 311 calls when that flooding is in your basement, but you probably wouldn’t think to call 311 when you’re two blocks away from your house and there’s a larger than normal puddle. We care about that because that’s an indication of a backup in our water system.”



Life Expectancy Chicago


Privacy and Security


Privacy was a huge concern for the Array of Things team. Public hearings were held to assess citizen’s concerns and allay fears over data collection, privacy, and security. While nodes do collect information on pedestrian traffic, they are, by design, unable to be compromised by third party interception of data. The nodes employ high performance computing, which processes images, uses artificial intelligence to extract data, and discards images – without sending any images to a server. In other words, the nodes are able to determine how many pedestrians are at a crossing, but the identity of the pedestrians are preserved as images are processed with the nodes and immediately destroyed. The nodes have limited storage; they don’t create or store an ongoing visual street view or transmit to the database, and the Array on the Argonne server is ethically treated as a research instrument.


Why the focus on cities?


Cities are facing extraordinary challenges as 20th century architecture struggles to keep pace with 21st century technical innovation and social needs. Cities must adapt to growing populations and ensure a sustainable use of resources, the mobility of people and ideas, stable job and living conditions. Problems in cities can be traced back to an imbalance between environment, infrastructure, and people. All three verticals are interconnected and urban planners and policy makers need to look across disciplines for opportunities to improve one vertical. Without smart data and the ability to predict outcomes, policy makers are blind. Cities should not just react to existing problems, they should proactively find ways to circumvent future problems through tweaks to zoning, building design, and energy use.

More of the world’s population are living in cities than ever before. In the U.S, 80% of GDP comes from cities. 70% of greenhouse gas emmisions come from cities. 70% of energy use is from cities. To have an impact on the environment and the future sustainability of society, starting in cities is a good idea. Arming policy-makers and data scientists with the tools to pre-empt a crisis is a critical step towards creating sustainable and livable cities.

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