Chicago Public Records: Traffic Studies & Crash Data

Transportation Illinois 4 Minutes Read · published February 04, 2026 Flag of Illinois

Chicago, Illinois residents and researchers often need official traffic studies and crash data for planning, safety analysis, or legal matters. This guide explains where those records are held, how to request them from the City of Chicago, typical timelines, and what departments handle traffic studies and crash reports. It covers both data already published on the city open data portal and non-public reports or detailed crash reports held by city agencies.

Where to look first

Many collision and traffic datasets are published on the City of Chicago Open Data portal; check published datasets and dashboards before filing a records request to avoid delays.[2]

Start with the city's open data portal to see if the dataset you need is already public.

How to request records

To request non-published traffic studies, engineering reports, or detailed crash reports, submit a public-records request under the City of Chicago FOIA process. Identify the records clearly (dates, locations, report numbers, authors or departments), state your preferred format (electronic CSV, PDF, or printed copies), and provide contact information. The city accepts requests via its FOIA portal and the methods described on the official FOIA page.[1]

  • Identify the records precisely: corridor, intersection, study title, or crash report number.
  • Specify file formats and date ranges to reduce search scope.
  • Provide a daytime phone and email for clarifying questions.

Penalties & Enforcement

The City of Chicago processes FOIA requests and the responsible offices for traffic studies and crash records include the Chicago Department of Transportation (CDOT) for traffic studies and the Chicago Police Department (CPD) for certain crash reports held by police. The City FOIA office administers the public-records process and appeals information. Specific monetary fines or administrative penalties for noncompliance are not specified on the cited City FOIA page; consult the Illinois Freedom of Information Act and the Illinois Attorney General for statutory enforcement provisions if needed.

Departmental responsibilities for traffic records are split—CDOT for studies and CPD for police crash reports.
  • Enforcer: City FOIA office and the custodian of records in CDOT or CPD for their respective files.
  • Fines/fees: fee details or standard copying charges are not specified on the cited City FOIA page.
  • Time limits: the city follows statutory FOIA response periods; the City page does not list an explicit deadline on its summary and refers to the governing statute.
  • Appeals/review: administrative appeal routes are described on the city FOIA page and may include review by the Public Access Counselor or court action per Illinois law.
  • Common violations: overly broad requests, failure to identify records, or requests for exempt personal data may be denied or redacted.

Applications & Forms

The City of Chicago provides an online FOIA request portal and instructions on its official FOIA page; use the portal form or submit in writing as directed on that page. If no specific form is required, the portal and instructions serve as the submission method.[1]

Action steps

  • Check the Chicago Open Data portal for published crash and traffic datasets before filing.
  • Prepare a clear FOIA request identifying records by dates, locations, and file types.
  • Submit via the City FOIA portal or methods listed on the official FOIA page.
  • Be prepared to pay duplication fees if the city charges them; ask for an estimate in the request.
  • If denied, follow the appeal steps on the FOIA page or consult the Illinois Attorney General's Public Access Counselor.

FAQ

Who holds traffic studies and crash reports for Chicago?
CDOT typically holds traffic engineering studies; CPD holds many police crash reports; the City FOIA office coordinates public records requests.
Can I get raw crash-location data?
Raw crash datasets are often published on the City of Chicago Open Data portal; for unpublished raw files, submit a FOIA request naming the dataset and desired format.
How long will a FOIA request take?
Response times follow statutory FOIA procedures; the City FOIA page should be consulted for process details and any posted timelines.

How-To

  1. Search the City of Chicago Open Data portal for existing crash and traffic datasets.
  2. Identify precisely which non-published records you need (dates, locations, report numbers, study titles).
  3. Prepare a FOIA request using the city portal or written submission form indicated on the City FOIA page.
  4. Specify format, delivery method, and contact details; request fee estimates if applicable.
  5. Submit the request and monitor communications; respond promptly to clarifying questions from the custodian.
  6. If denied, follow the appeal steps on the City FOIA page or seek review through the Illinois statutory process.

Key Takeaways

  • Check published open-data first to avoid unnecessary FOIA requests.
  • Be specific in requests: dates, locations, and file formats reduce delays.
  • CDOT and CPD are the primary custodians for traffic studies and crash reports respectively.

Help and Support / Resources

  1. [1] City of Chicago FOIA information and portal
  2. [2] City of Chicago Open Data - Crashes dataset

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