ThatCarHitMe.com
An Injuria.ai Company
YEAR-OVER-YEAR CRASH REPORT · CHICAGO, IL · DECEMBER 2023
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-2023-report
Monthly Traffic Safety Analysis
9,113 CRASHES IN
CHICAGO, IL
DECEMBER 2023
In December 2023, Chicago experienced 9,113 total crashes, an increase of 1.95% compared to the 8,939 crashes in December 2022. The most notable shift was a significant decrease in total fatalities, which dropped by 27.78% year-over-year.
9,113
▲ 1.9%was 8,939
Total Crash Events
13
▼ -27.8%was 18
Persons Killed
1,951
▲ 14.4%was 1,706
Persons Injured
2,861
▼ -4.5%was 2,995
Hit-and-Run Crashes
Note: "Persons Killed" (13) counts individual fatalities across all crash events. "Fatal" in the severity table below (12) counts crash events where at least one fatality occurred. A single crash can result in multiple fatalities. 18 crashes with unreported severity are not shown in the severity breakdown.
Source: Chicago Traffic Crashes · Socrata Open Data · 2023-12-01 to 2023-12-31 · Aggregate counts from crash, person, and vehicle records
Trend Summary
Overall, crash incidents in Chicago saw a slight increase of 1.95% year-over-year, rising from 8,939 crashes in December 2022 to 9,113 crashes in December 2023. Despite this, total fatalities decreased significantly by 27.78%, from 18 to 13, while total injuries increased by 14.36%, from 1,706 to 1,951.
2,861
Hit-and-Run Crashes — December 2023
▼ -4.5% vs prior (2,995)
Hit-and-run crashes decreased by 4.47% year-over-year, from 2,995 incidents in December 2022 to 2,861 in December 2023. The hit-and-run rate also saw a decrease of 2.1 percentage points, moving from 33.5% in the prior period to 31.4% in the current period, indicating a downward trend.
Vulnerable Road User Casualties
4
Pedestrians Killed
0
Cyclists Killed
9
Motorists Killed
0
Other Killed
258
Pedestrians Injured
69
Cyclists Injured
1,623
Motorists Injured
1
Other Injured
Source: Chicago Traffic Crashes · Socrata Open Data · 2023-12-01 to 2023-12-31 · Mode classified from person records (driver/passenger → motorist; pedestrian; bicyclist → cyclist; in-line skater / unspecified → other)
When Crashes Happen
The peak day for crashes remained Friday in both periods, with 1,870 crashes in December 2023 and 1,627 in December 2022. The peak hour also remained consistent at 5 PM, recording 771 crashes in the current period compared to 700 in the prior. Notably, crashes on Sundays increased by 29.28%, from 1,011 to 1,307, while crashes on Thursdays decreased by 20.44%, from 1,492 to 1,187.
Source: Chicago Traffic Crashes · Socrata Open Data · 2023-12-01 to 2023-12-31 · Crash date field aggregated by weekday
Source: Chicago Traffic Crashes · Socrata Open Data · 2023-12-01 to 2023-12-31 · Crash time field aggregated by hour (0-23)
Crash Severity Breakdown
Fatal crashes decreased by 29.41% year-over-year, from 17 in December 2022 to 12 in December 2023, with the fatal crash rate dropping from 0.19% to 0.13%. While serious injury crashes (severity A) decreased by 17 incidents, minor injury crashes (severity B) increased by 63, and possible injury crashes (severity C) rose by 80 incidents.
Severity is per crash event (most severe injury). 12 fatal crash events resulted in 13 persons killed.
Outcome by Severity (Crash Events)
Source: Chicago Traffic Crashes · Socrata Open Data · 2023-12-01 to 2023-12-31 · KABCO injury classification scale
Severity Distribution
Source: Chicago Traffic Crashes · Socrata Open Data · 2023-12-01 to 2023-12-31 · Most severe injury per crash record
Top Contributing Factors
Among contributing factors, 'FAILING TO YIELD RIGHT-OF-WAY' remained the most frequent, increasing by 94 incidents (9.39%) to 1,095. There was a significant 48.12% decrease in crashes attributed to 'WEATHER' (from 266 to 138 incidents), while crashes involving 'UNDER THE INFLUENCE OF ALCOHOL/DRUGS' increased notably by 53.33% (from 30 to 46 incidents). 'FOLLOWING TOO CLOSELY' saw a decrease of 55 incidents (-7.25%), dropping from 759 to 704.
Officer-Reported Primary Contributing Cause
Source: Chicago Traffic Crashes · Socrata Open Data · 2023-12-01 to 2023-12-31 · Officer-reported primary contributory cause per crash
Road & Environmental Conditions
Weather conditions saw a substantial shift, with crashes during 'RAIN' increasing by 139% (from 836 to 1,998 incidents), while crashes during 'SNOW' decreased by 84.75% (from 892 to 136 incidents). Correspondingly, crashes on 'WET' road surfaces increased by 36.43% (from 1,908 to 2,603 incidents), and those on 'SNOW OR SLUSH' surfaces decreased by 94.2% (from 965 to 56 incidents). Crashes in 'DARKNESS' conditions increased by 103 incidents, from 612 to 715.
Weather
Source: Chicago Traffic Crashes · Socrata Open Data · 2023-12-01 to 2023-12-31 · Weather condition at time of crash
Lighting
Source: Chicago Traffic Crashes · Socrata Open Data · 2023-12-01 to 2023-12-31 · Lighting condition field
Road Surface
Source: Chicago Traffic Crashes · Socrata Open Data · 2023-12-01 to 2023-12-31 · Road surface condition field
Vehicles & Demographics
The total number of vehicles involved in crashes increased by 2.07% year-over-year, from 18,170 to 18,546. Notably, bicycle involvement in crashes saw a significant increase of 68.25%, rising from 63 to 106 incidents. Toyota remained the most frequently involved vehicle make, increasing its count by 104, while Honda moved from the fifth to the fourth most common make, surpassing Nissan. The age group 16-20 saw a 23.22% increase in persons involved in crashes, and the 65+ age group increased by 16.63%.
Top Vehicle Makes (18,546 vehicles)
Source: Chicago Traffic Crashes · Socrata Open Data · 2023-12-01 to 2023-12-31 · Vehicle unit records
6,029 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 (19,775 persons with recorded sex)
Source: Chicago Traffic Crashes · Socrata Open Data · 2023-12-01 to 2023-12-31 · Person-level records linked to crash events
Speed Limit Zones
Crashes within a 30 mph speed limit zone increased by 282 incidents (4.34%), from 6,497 to 6,779, though fatalities in this zone decreased from 12 to 8. Conversely, crashes in 20 mph zones decreased by 90 incidents, from 415 to 325, and fatalities in this zone decreased from 1 to 0. Crashes in 45 mph zones increased from 61 to 71, resulting in one fatality in the current period compared to none in the prior.
Fatal crashes by zone: 25 mph: 1 of 666 (0.15%) · 30 mph: 8 of 6,779 (0.118%) · 35 mph: 2 of 597 (0.335%) · 45 mph: 1 of 71 (1.408%)
Source: Chicago Traffic Crashes · Socrata Open Data · 2023-12-01 to 2023-12-31 · 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: 2023-12-01 through 2023-12-31
- Report generated: June 1, 2026
Data Coverage
- Reporting period: 2023-12-01 through 2023-12-31 (31 days)
- Geographic scope: Chicago, IL
- Total crash records analyzed: 9,113
- Total persons involved: 20,152
- Total vehicles involved: 18,546
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/december-2023-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: 2023-12-01 – 2023-12-31
Generated: June 1, 2026 · All rights reserved