Average Daily Traffic Counts

Average Daily Traffic (ADT) counts around the City of Chicago. Data are collected from over 800 traffic and speed enforcement cameras 24/7/365. Traffic counts are a by-product of these cameras that are primarily used for other operational purposes. Data from the cameras are recorded, summarized, and assigned to a street segment through the Chicago Department of Transportation's (CDOT) Advanced Traffic Management System (ATMS). Each vendor uses proprietary algorithms to count vehicles from video and/or radar detection data. The daily count from a camera is assigned to the street segment where the camera is located. If there are multiple cameras on the same street segment, the daily count is the average of the counts from all cameras on the segment. If the camera is at the intersection monitoring all turning movements (e.g., traffic cameras), the counts are appropriately assigned to multiple segments converging at the intersection. Hence, the data are available for more segments than the number of cameras. Each daily count record in this dataset is the average of the daily count from the last thirty days. The 30-day average is used to normalize exceptional volumes for short periods. Information on each segment is provided with this data. These segments are quarter-mile to half-mile stretches of roadway. Occasionally, counts can be wrong due to unexpected device or field conditions, resulting in inaccurate daily totals for a certain period. When errors are identified, corrections are made, and such corrections may only be reflected in the data post-correction. By using this dataset, you are accepting any and all maps/data and information you may receive (the "data") "as is" and without any warranty or representation whatsoever, express or implied, whether for accuracy, timeliness, completeness, fitness for a particular purpose or otherwise. The information on this site is provided here for reference purposes only. While every effort is made to provide as much accurate information as possible, the City of Chicago, any of its departments, or any of its employees, cannot be held liable for the accuracy and completeness of this information. Data is available in the dataset from October 2020. New cameras are added on a rolling basis. Data accuracy and consistency are higher from May 2026 and later. Visual representation of daily ADT is also available on http://ChicagoTrafficTracker.com site.

Cite as: City of Chicago. Average Daily Traffic Counts. https://data.cityofchicago.org/d/gc7y-n4xa