ThatCarHitMe.com
An Injuria.ai Company
YEAR-OVER-YEAR CRASH REPORT · CHICAGO, IL · SEPTEMBER 2025
Purpose: Machine-readable JSON endpoint for AI agents, LLMs, researchers, and programmatic consumers. Returns all underlying crash data and AI-generated commentary without HTML.
Authentication: None required. Public endpoint.
GET: https://thatcarhitme.com/api/crash-data/reports/data/illinois/chicago/september-2025-report
Monthly Traffic Safety Analysis
9,042 CRASHES IN
CHICAGO, IL
SEPTEMBER 2025
Total crashes in September 2025 were 9,042, a decrease of 7.88% compared to 9,816 crashes in September 2024. The most notable shift was a 36.36% reduction in total fatalities, falling from 11 in the prior year to 7 in the current period. This indicates an overall improvement in traffic safety outcomes year-over-year.
9,042
▼ -7.9%was 9,816
Total Crash Events
7
▼ -36.4%was 11
Persons Killed
2,250
▼ -6.1%was 2,396
Persons Injured
2,607
▼ -14.7%was 3,056
Hit-and-Run Crashes
Note: "Persons Killed" (7) counts individual fatalities across all crash events. "Fatal" in the severity table below (6) counts crash events where at least one fatality occurred. A single crash can result in multiple fatalities. 13 crashes with unreported severity are not shown in the severity breakdown.
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-09-01 to 2025-09-30 · Aggregate counts from crash, person, and vehicle records
Trend Summary
Overall, crash data for September 2025 indicates a downward trend compared to September 2024. Total crashes decreased by 7.88% from 9,816 to 9,042, while total fatalities saw a significant reduction of 36.36%, falling from 11 to 7. Total injuries also declined by 6.09%, from 2,396 to 2,250.
2,607
Hit-and-Run Crashes — September 2025
▼ -14.7% vs prior (3,056)
Hit-and-run crashes decreased by 14.7%, from 3,056 in September 2024 to 2,607 in September 2025. Consequently, the hit-and-run crash rate declined from 31.1% to 28.8%, indicating a downward trend in the proportion of crashes involving a hit-and-run.
Vulnerable Road User Casualties
2
Pedestrians Killed
0
Cyclists Killed
5
Motorists Killed
0
Other Killed
236
Pedestrians Injured
255
Cyclists Injured
1,745
Motorists Injured
14
Other Injured
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-09-01 to 2025-09-30 · Mode classified from person records (driver/passenger → motorist; pedestrian; bicyclist → cyclist; in-line skater / unspecified → other)
When Crashes Happen
The peak day for crashes shifted from Sunday in September 2024, with 1,551 crashes, to Tuesday in September 2025, with 1,563 crashes. The peak crash hour remained 3 PM in both periods, though the count decreased from 814 crashes in September 2024 to 767 crashes in September 2025.
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-09-01 to 2025-09-30 · Crash date field aggregated by weekday
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-09-01 to 2025-09-30 · Crash time field aggregated by hour (0-23)
Crash Severity Breakdown
Fatal crashes decreased by 45.45%, from 11 in September 2024 to 6 in September 2025, with the fatal crash rate dropping from 0.11% to 0.07%. Serious injury crashes (severity A) decreased by 15.48% (from 168 to 142), and minor injury crashes (severity B) decreased by 6.92% (from 954 to 888). Possible injury crashes (severity C) increased by 2.39%, from 585 to 599.
Severity is per crash event (most severe injury). 6 fatal crash events resulted in 7 persons killed.
Outcome by Severity (Crash Events)
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-09-01 to 2025-09-30 · KABCO injury classification scale
Severity Distribution
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-09-01 to 2025-09-30 · Most severe injury per crash record
Top Contributing Factors
“Failing to Yield Right-of-Way” remained the top contributing factor, decreasing by 92 crashes (7.74% change in count) from 1,189 to 1,097. “Following Too Closely” saw a slight increase of 7 crashes (0.81% change in count), from 860 to 867. “Driving Skills/Knowledge/Experience” increased by 29 crashes (9.01% change in count), from 322 to 351, while “Improper Overtaking/Passing” decreased by 18 crashes (3.24% change in count), from 555 to 537.
Officer-Reported Primary Contributing Cause
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-09-01 to 2025-09-30 · Officer-reported primary contributory cause per crash
Road & Environmental Conditions
Crashes occurring in clear weather decreased by 282, from 8,410 to 8,128, while crashes in rainy conditions saw a substantial reduction of 366, from 564 to 198. Crashes during daylight hours decreased by 329, from 6,636 to 6,307, and those on wet road surfaces decreased by 357, from 649 to 292.
Weather
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-09-01 to 2025-09-30 · Weather condition at time of crash
Lighting
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-09-01 to 2025-09-30 · Lighting condition field
Road Surface
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-09-01 to 2025-09-30 · Road surface condition field
Vehicles & Demographics
The total number of vehicles involved in crashes decreased by 7.91%, from 20,006 to 18,423. While the number of driver-involved vehicles decreased by 7.65% (16,677 to 15,401), bicycle-involved vehicles increased by 18.75%, from 304 to 361. The top five vehicle makes involved in crashes (Toyota, Chevrolet, Ford, Honda, Nissan) remained consistent across both periods.
Top Vehicle Makes (18,423 vehicles)
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-09-01 to 2025-09-30 · Vehicle unit records
5,704 persons with unknown or unrecorded age excluded from age chart. Age=0 in Chicago records is a sentinel for unknown/unrecorded age (not infants) and is grouped with nulls.
Sex Distribution (19,505 persons with recorded sex)
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-09-01 to 2025-09-30 · Person-level records linked to crash events
Speed Limit Zones
The total number of fatal crashes across all speed zones decreased from 11 in September 2024 to 6 in September 2025. Fatal crashes in 30 mph zones, which accounted for the majority of crashes in both periods, decreased by 62.5% from 8 to 3, and their fatal rate dropped from 0.11% to 0.045%. While 30 mph remained a primary zone for fatal incidents, fatal crashes in other speed zones shifted from 25 mph and 35 mph in the prior year to 20 mph and 40 mph in the current year.
Fatal crashes by zone: 20 mph: 2 of 386 (0.518%) · 30 mph: 3 of 6,614 (0.045%) · 40 mph: 1 of 91 (1.099%)
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-09-01 to 2025-09-30 · Posted speed limit at crash location
Data Sources & Methodology
Primary Data Source
All crash data in this report is sourced from Chicago Traffic Crashes, accessed programmatically via the Socrata Open Data API (SODA). This dataset contains official police-reported motor vehicle traffic crash records maintained by the reporting jurisdiction's law enforcement agency. Records are published to the open data portal by the municipality and are subject to the portal's terms of use.
Data Retrieval
- Access method: Socrata Open Data API (SoQL queries)
- Data format: Structured JSON via REST API
- Record types queried: Crash events, person records, and vehicle unit records
- Date filter applied: 2025-09-01 through 2025-09-30
- Report generated: June 1, 2026
Data Coverage
- Reporting period: 2025-09-01 through 2025-09-30 (30 days)
- Geographic scope: Chicago, IL
- Total crash records analyzed: 9,042
- Total persons involved: 19,895
- Total vehicles involved: 18,423
Analytical Methodology
- Severity classification: Uses the KABCO injury scale (K=Fatal, A=Incapacitating injury, B=Non-incapacitating injury, C=Possible injury, O=No injury/property damage only), the standard classification in U.S. Model Minimum Uniform Crash Criteria (MMUCC). Severity is assigned per crash event based on the most severe injury in that crash. A single fatal crash (K) may involve multiple fatalities; therefore the "Persons Killed" count in the headline KPIs may differ from the "Fatal" crash count in the severity breakdown.
- Contributing factors: Reflect the officer-determined primary contributory cause recorded at the time of the crash report. These are preliminary determinations and may not reflect final investigation findings.
- Hit-and-run classification: Based on the hit-and-run indicator field in the official crash report, as determined by the responding officer at the scene.
- Temporal analysis: Day-of-week and hour-of-day distributions are computed from the crash date/time timestamp in each record.
- Demographics: Age and sex distributions are drawn from person-level records linked to each crash event. A single crash may involve multiple persons.
- Vehicle data: Make information is drawn from vehicle unit records linked to each crash event.
- AI commentary: Narrative sections are generated by Google Gemini (large language model) based on the structured data. Commentary is descriptive, not predictive, and should not be interpreted as expert opinion.
Limitations & Disclaimers
- Only crashes reported to and documented by law enforcement are included. Minor incidents, unreported crashes, and near-misses are not captured in this dataset.
- Data reflects conditions at the time of the initial police report and may be subject to subsequent corrections, reclassifications, or supplements by the reporting agency.
- Open data portal records may experience a publication lag - recently occurring crashes may not yet appear in the dataset at the time of report generation.
- AI-generated commentary is produced by a large language model and is intended to highlight patterns in the data. It does not constitute legal, medical, or professional analysis.
- Percentages are calculated from reported data and are subject to rounding.
Non-Affiliation Disclosure
This report is produced independently by ThatCarHitMe.com (Injuria.ai). It is not affiliated with, endorsed by, or produced in partnership with any law enforcement agency, municipal government, state department of transportation, or the National Highway Traffic Safety Administration (NHTSA). Data is sourced from publicly available government open data portals.
Data License
The underlying crash data is provided under the municipality's Open Data Terms of Use and is made available to the public for unrestricted use. This analysis and report is © 2026 Injuria.ai and may be cited with attribution using the suggested citation below.
Corrections & Feedback
If you believe any data in this report is inaccurate or have questions about our methodology, please contact: data@injuria.ai. We are committed to accuracy and will issue corrections promptly.
Suggested Citation
ThatCarHitMe.com (Injuria.ai). "Chicago, IL Crash Intelligence Report." Published June 1, 2026. Data source: Chicago Traffic Crashes, Socrata Open Data. Available at: https://thatcarhitme.com/crash-data/illinois/chicago/september-2025-report
About the Publisher
ThatCarHitMe.com is a crash data intelligence platform developed by Injuria.ai, a legal technology company specializing in traffic safety analytics. We aggregate and analyze publicly available government crash data to produce structured intelligence reports for communities, researchers, journalists, and legal professionals. Our reports combine programmatic data retrieval from official open data portals with AI-assisted narrative analysis.
Questions about this report's data or methodology: data@injuria.ai
ThatCarHitMe.com · An Injuria.ai Company
ThatCarHitMe.com
An Injuria.ai Company
Crash Data Intelligence
Data: Chicago Traffic Crashes · Socrata
Period: 2025-09-01 – 2025-09-30
Generated: June 1, 2026 · All rights reserved