ThatCarHitMe.com
An Injuria.ai Company
YEAR-OVER-YEAR CRASH REPORT · CHICAGO, IL · 2021
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/2021-annual-report
Yearly Traffic Safety Analysis
108,767 CRASHES IN
CHICAGO, IL
2021
In 2021, Chicago recorded 108,767 traffic crashes, an 18.1% increase from the 92,096 crashes reported in 2020. This rise in collisions was accompanied by an increase in both fatalities, from 153 to 166, and total injuries, from 19,770 to 22,224. The most significant year-over-year change was the overall growth in crash volume across the city.
108,767
▲ 18.1%was 92,096
Total Crash Events
166
▲ 8.5%was 153
Persons Killed
22,224
▲ 12.4%was 19,770
Persons Injured
37,263
▲ 22.2%was 30,498
Hit-and-Run Crashes
Note: "Persons Killed" (166) counts individual fatalities across all crash events. "Fatal" in the severity table below (156) counts crash events where at least one fatality occurred. A single crash can result in multiple fatalities. 248 crashes with unreported severity are not shown in the severity breakdown.
Source: Chicago Traffic Crashes · Socrata Open Data · 2021-01-01 to 2021-12-31 · Aggregate counts from crash, person, and vehicle records
Trend Summary
The data indicates a clear upward trend in traffic incidents year-over-year. Total crashes increased by 18.1%, rising from 92,096 in 2020 to 108,767 in 2021. This trend extends to crash outcomes, with total injuries increasing by 12.4% and fatalities rising by 8.5% over the same period.
37,263
Hit-and-Run Crashes — 2021
▲ 22.2% vs prior (30,498)
Hit-and-run incidents increased in both absolute numbers and as a proportion of total crashes from 2020 to 2021. The total count of hit-and-run crashes rose by 22.2%, from 30,498 to 37,263. The hit-and-run rate also trended upward, increasing from 33.1% of all crashes in 2020 to 34.3% in 2021.
Vulnerable Road User Casualties
46
Pedestrians Killed
7
Cyclists Killed
113
Motorists Killed
0
Other Killed
2,174
Pedestrians Injured
1,142
Cyclists Injured
18,888
Motorists Injured
20
Other Injured
Source: Chicago Traffic Crashes · Socrata Open Data · 2021-01-01 to 2021-12-31 · Mode classified from person records (driver/passenger → motorist; pedestrian; bicyclist → cyclist; in-line skater / unspecified → other)
When Crashes Happen
Temporal crash patterns showed some consistency and some shifts between 2020 and 2021. Friday remained the peak day for crashes in both years, with a 17.5% increase in Friday collisions in 2021. However, the peak hour for crashes shifted from 4 PM in 2020 to 3 PM in 2021, and the volume of crashes during the 3 PM hour increased by 23.3% year-over-year.
Source: Chicago Traffic Crashes · Socrata Open Data · 2021-01-01 to 2021-12-31 · Crash date field aggregated by weekday
Source: Chicago Traffic Crashes · Socrata Open Data · 2021-01-01 to 2021-12-31 · Crash time field aggregated by hour (0-23)
Crash Severity Breakdown
While the absolute number of fatal crashes rose from 134 in 2020 to 156 in 2021, the fatal crash rate as a percentage of all crashes saw a slight decrease from 0.15% to 0.14%. Similarly, the proportion of crashes resulting in any type of injury (Serious, Minor, or Possible) declined from 15.3% of all crashes in 2020 to 14.9% in 2021. Consequently, the share of crashes with no reported injuries increased from 84.4% to 84.8% year-over-year.
Severity is per crash event (most severe injury). 156 fatal crash events resulted in 166 persons killed.
Outcome by Severity (Crash Events)
Source: Chicago Traffic Crashes · Socrata Open Data · 2021-01-01 to 2021-12-31 · KABCO injury classification scale
Severity Distribution
Source: Chicago Traffic Crashes · Socrata Open Data · 2021-01-01 to 2021-12-31 · Most severe injury per crash record
Top Contributing Factors
The top two primary contributing factors remained "Failing to Yield Right-of-Way" and "Following Too Closely" in both 2020 and 2021. The count of crashes attributed to failing to yield increased by 15.2% from 9,708 to 11,183. A notable shift occurred in the third position, with "Improper Overtaking/Passing" displacing "Failing to Reduce Speed to Avoid Crash," as the count for improper passing crashes surged by 31.7% year-over-year from 3,993 to 5,259 incidents.
Officer-Reported Primary Contributing Cause
Source: Chicago Traffic Crashes · Socrata Open Data · 2021-01-01 to 2021-12-31 · Officer-reported primary contributory cause per crash
Road & Environmental Conditions
The distribution of crashes by lighting condition remained stable year-over-year, with daylight crashes accounting for approximately 63% of incidents in both periods. However, there was a notable shift in crashes occurring on adverse road surfaces. The number of crashes on roads with "Snow or Slush" nearly doubled, rising from 2,582 in 2020 to 5,168 in 2021, and their share of total crashes increased from 2.8% to 4.8%.
Weather
Source: Chicago Traffic Crashes · Socrata Open Data · 2021-01-01 to 2021-12-31 · Weather condition at time of crash
Lighting
Source: Chicago Traffic Crashes · Socrata Open Data · 2021-01-01 to 2021-12-31 · Lighting condition field
Road Surface
Source: Chicago Traffic Crashes · Socrata Open Data · 2021-01-01 to 2021-12-31 · Road surface condition field
Vehicles & Demographics
The total number of vehicles involved in crashes grew from 189,607 in 2020 to 222,458 in 2021. While Chevrolet remained the most common vehicle make involved in crashes in both years, a shift occurred in the rankings for the second and third positions. In 2021, Toyota (21,716 vehicles) surpassed Ford (21,495 vehicles) to become the second most frequently involved make, a change from 2020 when Ford held the number two spot. The age distribution of persons involved in crashes remained proportionally consistent year-over-year.
Top Vehicle Makes (222,458 vehicles)
Source: Chicago Traffic Crashes · Socrata Open Data · 2021-01-01 to 2021-12-31 · Vehicle unit records
73,895 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 (229,901 persons with recorded sex)
Source: Chicago Traffic Crashes · Socrata Open Data · 2021-01-01 to 2021-12-31 · Person-level records linked to crash events
Speed Limit Zones
Crashes in 30 mph speed zones continued to dominate, accounting for over 72% of all incidents in both 2020 and 2021, with the count increasing by 18.9% year-over-year. Fatalities within this zone also rose by 24.3%, from 103 to 128. Notably, the number of crashes in higher speed zones (40 mph and above) grew at a faster rate than the overall average, increasing by 28.1% from 1,564 incidents in 2020 to 2,003 in 2021.
Fatal crashes by zone: 15 mph: 3 of 4,161 (0.072%) · 25 mph: 8 of 7,196 (0.111%) · 30 mph: 128 of 79,593 (0.161%) · 35 mph: 10 of 7,033 (0.142%) · 40 mph: 3 of 1,083 (0.277%) · 45 mph: 4 of 766 (0.522%)
Source: Chicago Traffic Crashes · Socrata Open Data · 2021-01-01 to 2021-12-31 · 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: 2021-01-01 through 2021-12-31
- Report generated: June 1, 2026
Data Coverage
- Reporting period: 2021-01-01 through 2021-12-31 (365 days)
- Geographic scope: Chicago, IL
- Total crash records analyzed: 108,767
- Total persons involved: 233,799
- Total vehicles involved: 222,458
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/2021-annual-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: 2021-01-01 – 2021-12-31
Generated: June 1, 2026 · All rights reserved