ThatCarHitMe.com
An Injuria.ai Company
YEAR-OVER-YEAR CRASH REPORT · CHICAGO, IL · AUGUST 2018
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/august-2018-report
Monthly Traffic Safety Analysis
10,212 CRASHES IN
CHICAGO, IL
AUGUST 2018
Total crashes in Chicago increased from 7,685 in August 2017 to 10,212 in August 2018, representing a 32.88% increase. The most notable year-over-year shift was a 42.40% increase in hit-and-run crashes, which rose from 1,953 to 2,781.
10,212
▲ 32.9%was 7,685
Total Crash Events
13
▲ 18.2%was 11
Persons Killed
2,037
▲ 42.1%was 1,434
Persons Injured
2,781
▲ 42.4%was 1,953
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. 21 crashes with unreported severity are not shown in the severity breakdown.
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-08-01 to 2018-08-31 · Aggregate counts from crash, person, and vehicle records
Trend Summary
Overall crash data for August 2018 indicates a significant upward trend compared to August 2017. Total crashes increased by 32.88%, rising from 7,685 to 10,212. This notable increase suggests a worsening trend in crash incidents year-over-year.
2,781
Hit-and-Run Crashes — August 2018
▲ 42.4% vs prior (1,953)
The number of hit-and-run crashes significantly increased by 42.40%, rising from 1,953 in August 2017 to 2,781 in August 2018. Concurrently, the hit-and-run rate also trended upward, increasing from 25.4% to 27.2% of all crashes.
Vulnerable Road User Casualties
2
Pedestrians Killed
2
Cyclists Killed
8
Motorists Killed
1
Other Killed
222
Pedestrians Injured
220
Cyclists Injured
1,591
Motorists Injured
4
Other Injured
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-08-01 to 2018-08-31 · 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 Wednesday in August 2017, with 1,286 crashes, to Friday in August 2018, with 1,821 crashes. While the peak hour remained 5 p.m. in both periods, the number of crashes at 5 p.m. increased by 29.76%, from 588 to 763.
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-08-01 to 2018-08-31 · Crash date field aggregated by weekday
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-08-01 to 2018-08-31 · Crash time field aggregated by hour (0-23)
Crash Severity Breakdown
The fatal crash rate decreased slightly from 0.14% in August 2017 to 0.12% in August 2018, despite total fatalities increasing from 11 to 13. The proportion of injury-involved crashes (Serious, Minor, Possible) increased from 13.66% of total crashes in August 2017 to 14.76% in August 2018.
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 · 2018-08-01 to 2018-08-31 · KABCO injury classification scale
Severity Distribution
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-08-01 to 2018-08-31 · Most severe injury per crash record
Top Contributing Factors
The top five contributing factors remained consistent in ranking between the two periods, all showing increased counts. 'Failing to Yield Right-of-Way' crashes increased by 288 (31.03% increase in count), 'Following Too Closely' crashes increased by 233 (25.33% increase in count), and 'Improper Backing' crashes increased by 131 (36.59% increase in count).
Officer-Reported Primary Contributing Cause
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-08-01 to 2018-08-31 · Officer-reported primary contributory cause per crash
Road & Environmental Conditions
Crashes occurring in clear weather conditions increased by 28.92% (from 6,827 to 8,801), while crashes in rainy conditions saw a more substantial 92.54% increase (from 362 to 697). Similarly, crashes on wet road surfaces increased by 90.06% (from 483 to 918), leading to an increase in the proportion of crashes on wet roads from 6.28% to 8.99%.
Weather
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-08-01 to 2018-08-31 · Weather condition at time of crash
Lighting
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-08-01 to 2018-08-31 · Lighting condition field
Road Surface
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-08-01 to 2018-08-31 · Road surface condition field
Vehicles & Demographics
The total number of vehicles involved in crashes increased by 33.37%, from 15,676 to 20,907. Among vehicle types, 'DRIVER' vehicles increased by 32.47% and 'PARKED' vehicles by 35.59%. The age group '0-15' saw a notable 44.73% increase in persons involved, rising from 588 to 851.
Top Vehicle Makes (20,907 vehicles)
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-08-01 to 2018-08-31 · Vehicle unit records
6,394 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 (22,420 persons with recorded sex)
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-08-01 to 2018-08-31 · Person-level records linked to crash events
Speed Limit Zones
Crashes occurring in 30 mph speed zones, which account for the majority of incidents, increased by 35.79% from 5,552 to 7,539. The fatal crash rate within 30 mph zones also slightly increased from 0.108% to 0.119%. Conversely, the fatal crash rate in 25 mph zones decreased from 0.411% to 0.345%.
Fatal crashes by zone: 25 mph: 2 of 580 (0.345%) · 30 mph: 9 of 7,539 (0.119%) · 35 mph: 1 of 716 (0.14%)
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-08-01 to 2018-08-31 · 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: 2018-08-01 through 2018-08-31
- Report generated: June 1, 2026
Data Coverage
- Reporting period: 2018-08-01 through 2018-08-31 (31 days)
- Geographic scope: Chicago, IL
- Total crash records analyzed: 10,212
- Total persons involved: 22,708
- Total vehicles involved: 20,907
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/august-2018-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: 2018-08-01 – 2018-08-31
Generated: June 1, 2026 · All rights reserved