Array of Things — Chicago's Open-Source Urban Sensor Network

Argonne National Laboratory and the University of Chicago's Urban Center for Computation and Data, funded by the National Science Foundation, began deploying the Array of Things (AoT) sensor network across Chicago in 2016. Described in its own project materials as a 'fitness tracker for the city,' each node measures air quality, noise, heat, light and pedestrian/vehicle counts street by street.

The platform's design and early results were documented in a peer-reviewed ACM conference paper ('Array of Things: a scientific research instrument in the public way,' 2017) and in Argonne/Department of Energy technical reports. These sources describe extensive community engagement with Chicago neighbourhood organisations before installation, treated as essential rather than optional since community rejection could have stalled deployment entirely. The underlying open-source edge-computing platform, Waggle, was expanded in 2021-22 into 'Project Eclipse,' a joint deployment with the City of Chicago, Microsoft Research's Urban Innovation team and outdoor-advertising firm JCDecaux that placed air-quality sensors on 115 Chicago bus shelters.

MIT Technology Review (2022) reports that the Waggle platform has since been adopted in research deployments beyond Chicago.

The evidence found is strongest on engineering performance and data quality, and weaker on downstream policy impact: none of the sources reviewed independently demonstrate that the sensor data measurably changed a city policy outcome, and no quantified equity results for specific underserved neighbourhoods were found.