ThatCarHitMe.com
An Injuria.ai Company
YEAR-OVER-YEAR CRASH REPORT · CHICAGO, IL · APRIL 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/april-2018-report
Monthly Traffic Safety Analysis
9,648 CRASHES IN
CHICAGO, IL
APRIL 2018
In April 2018, Chicago experienced a significant increase in traffic crashes and fatalities compared to April 2017. Total crashes rose from 5024 to 9648, marking a 92.04% increase year-over-year. The most notable shift was in fatalities, which increased from 2 in April 2017 to 11 in April 2018, a 450% rise.
9,648
▲ 92.0%was 5,024
Total Crash Events
11
▲ 450.0%was 2
Persons Killed
1,784
▲ 250.5%was 509
Persons Injured
2,559
▲ 83.6%was 1,394
Hit-and-Run Crashes
Note: "Persons Killed" (11) counts individual fatalities across all crash events. "Fatal" in the severity table below (11) 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 · 2018-04-01 to 2018-04-30 · Aggregate counts from crash, person, and vehicle records
Trend Summary
Overall, crash data indicates a substantial upward trend year-over-year. Total crashes increased by 4624, from 5024 in April 2017 to 9648 in April 2018. This represents a 92.04% increase in the total number of crash incidents.
2,559
Hit-and-Run Crashes — April 2018
▲ 83.6% vs prior (1,394)
The number of hit-and-run crashes increased by 1165, from 1394 in April 2017 to 2559 in April 2018. Despite this increase in count, the hit-and-run rate decreased slightly from 27.7% of total crashes in April 2017 to 26.5% in April 2018.
Vulnerable Road User Casualties
7
Pedestrians Killed
0
Cyclists Killed
4
Motorists Killed
0
Other Killed
236
Pedestrians Injured
75
Cyclists Injured
1,472
Motorists Injured
1
Other Injured
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-04-01 to 2018-04-30 · Mode classified from person records (driver/passenger → motorist; pedestrian; bicyclist → cyclist; in-line skater / unspecified → other)
When Crashes Happen
The temporal patterns of crashes shifted year-over-year, with the peak day changing from Saturday in April 2017 (938 crashes) to Monday in April 2018 (1696 crashes). The peak hour also shifted from 3 PM in April 2017 (406 crashes) to 4 PM in April 2018 (715 crashes), indicating a later afternoon peak in the current period.
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-04-01 to 2018-04-30 · Crash date field aggregated by weekday
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-04-01 to 2018-04-30 · Crash time field aggregated by hour (0-23)
Crash Severity Breakdown
The severity distribution shows an increase in fatal and injury crashes. The fatal crash rate rose from 0.04% in April 2017 to 0.11% in April 2018. Serious injuries (Severity A) as a proportion of total crashes increased from 0.9% to 1.8%, while minor injuries (Severity B) increased from 3.7% to 7.4% year-over-year.
Outcome by Severity (Crash Events)
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-04-01 to 2018-04-30 · KABCO injury classification scale
Severity Distribution
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-04-01 to 2018-04-30 · Most severe injury per crash record
Top Contributing Factors
Contributing factors saw substantial increases in counts across the board. 'Failing to Yield Right-of-Way' increased by 611 crashes (118.4% change in count) from 516 to 1127, becoming the top factor in April 2018 with an 11.7% share. 'Following Too Closely' also rose significantly by 393 crashes (62.5% change in count) from 629 to 1022, holding a 10.6% share in the current period.
Officer-Reported Primary Contributing Cause
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-04-01 to 2018-04-30 · Officer-reported primary contributory cause per crash
Road & Environmental Conditions
There was a notable shift in adverse weather and road conditions contributing to crashes. Crashes occurring during 'SNOW' weather conditions increased from 2 in April 2017 to 507 in April 2018. Similarly, crashes on 'SNOW OR SLUSH' road surfaces increased from 1 to 207, and crashes on 'ICE' road surfaces appeared with 199 incidents in April 2018, having not been recorded in April 2017.
Weather
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-04-01 to 2018-04-30 · Weather condition at time of crash
Lighting
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-04-01 to 2018-04-30 · Lighting condition field
Road Surface
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-04-01 to 2018-04-30 · Road surface condition field
Vehicles & Demographics
The total number of vehicles involved in crashes increased from 10131 in April 2017 to 19692 in April 2018. The number of pedestrians involved as vehicle types rose from 69 to 274, and bicycles from 51 to 106. Top vehicle makes like Chevrolet, Toyota, and Ford maintained their leading positions, with their involvement counts increasing proportionally to the overall rise in crashes.
Top Vehicle Makes (19,692 vehicles)
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-04-01 to 2018-04-30 · Vehicle unit records
5,928 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 (21,283 persons with recorded sex)
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-04-01 to 2018-04-30 · Person-level records linked to crash events
Speed Limit Zones
Crashes in the 30 mph speed limit zone increased from 3708 to 7138, accounting for the majority of crashes in both periods. Fatalities in the 30 mph zone rose from 2 in April 2017 to 9 in April 2018, with the fatal rate in this zone increasing from 0.054% to 0.126%. Additionally, 15 mph and 35 mph zones, which had no fatalities in April 2017, each recorded 1 fatal crash in April 2018.
Fatal crashes by zone: 15 mph: 1 of 306 (0.327%) · 30 mph: 9 of 7,138 (0.126%) · 35 mph: 1 of 657 (0.152%)
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-04-01 to 2018-04-30 · 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: 2018-04-01 through 2018-04-30
- Report generated: June 1, 2026
Data Coverage
- Reporting period: 2018-04-01 through 2018-04-30 (30 days)
- Geographic scope: Chicago, IL
- Total crash records analyzed: 9,648
- Total persons involved: 21,596
- Total vehicles involved: 19,692
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/april-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: 2018-04-01 – 2018-04-30
Generated: June 1, 2026 · All rights reserved