ThatCarHitMe.com
An Injuria.ai Company
YEAR-OVER-YEAR CRASH REPORT · CHICAGO, IL · DECEMBER 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/december-2025-report
Monthly Traffic Safety Analysis
8,626 CRASHES IN
CHICAGO, IL
DECEMBER 2025
In December 2025, there were 8626 total crashes, a decrease of 1.84% compared to 8788 crashes in December 2024. The most notable shift was a significant increase in fatalities, rising from 6 in the prior period to 10 in the current period, representing a 66.67% increase. Total injuries decreased by 11.16% year-over-year, from 1873 to 1664.
8,626
▼ -1.8%was 8,788
Total Crash Events
10
▲ 66.7%was 6
Persons Killed
1,664
▼ -11.2%was 1,873
Persons Injured
2,586
▼ -0.4%was 2,597
Hit-and-Run Crashes
Note: "Persons Killed" (10) counts individual fatalities across all crash events. "Fatal" in the severity table below (9) counts crash events where at least one fatality occurred. A single crash can result in multiple fatalities. 23 crashes with unreported severity are not shown in the severity breakdown.
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-12-01 to 2025-12-31 · Aggregate counts from crash, person, and vehicle records
Trend Summary
The overall trend for total crashes in December 2025 shows a slight decrease of 1.84% compared to the prior year. However, fatalities experienced a substantial increase of 66.67%, rising from 6 to 10. Conversely, total injuries decreased by 11.16% year-over-year.
2,586
Hit-and-Run Crashes — December 2025
▼ -0.4% vs prior (2,597)
The number of hit-and-run crashes slightly decreased from 2597 in December 2024 to 2586 in December 2025. However, the hit-and-run rate increased from 29.6% to 30% of total crashes. This indicates that while the absolute count of hit-and-run incidents saw a minor reduction, their proportion relative to all crashes slightly rose.
Vulnerable Road User Casualties
6
Pedestrians Killed
0
Cyclists Killed
4
Motorists Killed
0
Other Killed
195
Pedestrians Injured
33
Cyclists Injured
1,434
Motorists Injured
2
Other Injured
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-12-01 to 2025-12-31 · 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 Friday with 1400 crashes in December 2024 to Tuesday with 1572 crashes in December 2025. The peak hour also shifted from 5p with 711 crashes in the prior period to 3p with 681 crashes in the current period. Overall, the distribution of crashes by day of week and hour showed changes in peak times.
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-12-01 to 2025-12-31 · Crash date field aggregated by weekday
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-12-01 to 2025-12-31 · Crash time field aggregated by hour (0-23)
Crash Severity Breakdown
Fatal crashes increased from 5 in December 2024 to 9 in December 2025, though the proportion of fatal crashes remained at 0.1%. Serious injury crashes (severity A) increased from 88 to 105, and their share of total crashes rose from 1.0% to 1.2%. Minor injury crashes (severity B) decreased from 729 to 583, with their proportion falling from 8.3% to 6.8% of total crashes.
Severity is per crash event (most severe injury). 9 fatal crash events resulted in 10 persons killed.
Outcome by Severity (Crash Events)
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-12-01 to 2025-12-31 · KABCO injury classification scale
Severity Distribution
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-12-01 to 2025-12-31 · Most severe injury per crash record
Top Contributing Factors
Failing to Yield Right-of-Way remained the top contributing factor, decreasing by 191 crashes (a 16.51% decrease in count) from 1157 to 966. Following Too Closely, the second-ranked factor, increased by 31 crashes (a 4.37% increase in count) from 709 to 740. Improper Overtaking/Passing, the third-ranked factor, decreased by 95 crashes (a 17.76% decrease in count) from 535 to 440.
Officer-Reported Primary Contributing Cause
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-12-01 to 2025-12-31 · Officer-reported primary contributory cause per crash
Road & Environmental Conditions
There was a significant shift in weather and road surface conditions, with crashes occurring in snowy weather increasing from 167 to 1088, and snow or slush road surface crashes increasing from 101 to 1282. Conversely, crashes in clear weather decreased by 704 and on dry road surfaces decreased by 1540. Crashes during rain also decreased by 595, indicating a shift towards more winter-like conditions in the current period.
Weather
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-12-01 to 2025-12-31 · Weather condition at time of crash
Lighting
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-12-01 to 2025-12-31 · Lighting condition field
Road Surface
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-12-01 to 2025-12-31 · Road surface condition field
Vehicles & Demographics
The total number of vehicles involved in crashes decreased from 17862 to 17453 year-over-year. The top five vehicle makes involved in crashes remained consistent, with Toyota, Chevrolet, and Ford leading in both periods. All age groups of persons involved in crashes, except for those 65 and older, saw a decrease in counts from the prior to the current period.
Top Vehicle Makes (17,453 vehicles)
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-12-01 to 2025-12-31 · Vehicle unit records
5,172 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 below reflects all 18,480 persons.
Sex Distribution (18,480 persons)
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-12-01 to 2025-12-31 · Person-level records linked to crash events
Speed Limit Zones
The 30 mph speed zone remained the most common for crashes in both periods, accounting for 73.83% of crashes in December 2024 and 73.69% in December 2025. Fatal crashes in the 30 mph zone increased from 4 to 6 year-over-year. Additionally, fatal crashes appeared in the 10 mph, 25 mph, and 40 mph zones in the current period, where none were recorded in the prior period.
Fatal crashes by zone: 10 mph: 1 of 263 (0.38%) · 25 mph: 1 of 687 (0.146%) · 30 mph: 6 of 6,357 (0.094%) · 40 mph: 1 of 107 (0.935%)
Source: Chicago Traffic Crashes · Socrata Open Data · 2025-12-01 to 2025-12-31 · 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: 2025-12-01 through 2025-12-31
- Report generated: May 20, 2026
Data Coverage
- Reporting period: 2025-12-01 through 2025-12-31 (31 days)
- Geographic scope: Chicago, IL
- Total crash records analyzed: 8,626
- Total persons involved: 18,480
- Total vehicles involved: 17,453
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 May 20, 2026. Data source: Chicago Traffic Crashes, Socrata Open Data. Available at: https://thatcarhitme.com/crash-data/illinois/chicago/december-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: 2025-12-01 – 2025-12-31
Generated: May 20, 2026 · All rights reserved