ThatCarHitMe.com
An Injuria.ai Company
YEAR-OVER-YEAR CRASH REPORT · CHICAGO, IL · MAY 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/may-2018-report
Monthly Traffic Safety Analysis
10,714 CRASHES IN
CHICAGO, IL
MAY 2018
In May 2018, Chicago experienced 10,714 total crashes, a significant increase from 5,847 crashes in May 2017. This represents an 83.24% rise in overall crash incidents year-over-year. The most notable shift was a 219.58% increase in total injuries, rising from 674 to 2,154.
10,714
▲ 83.2%was 5,847
Total Crash Events
7
▲ 16.7%was 6
Persons Killed
2,154
▲ 219.6%was 674
Persons Injured
2,761
▲ 76.6%was 1,563
Hit-and-Run Crashes
Note: "Persons Killed" (7) counts individual fatalities across all crash events. "Fatal" in the severity table below (7) counts crash events where at least one fatality occurred. A single crash can result in multiple fatalities. 20 crashes with unreported severity are not shown in the severity breakdown.
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-05-01 to 2018-05-31 · Aggregate counts from crash, person, and vehicle records
Trend Summary
The overall trend indicates a substantial increase in traffic crashes in Chicago, with total incidents rising by 4,867 from May 2017 to May 2018. This constitutes an 83.24% increase year-over-year. Total fatalities also increased, from 6 in May 2017 to 7 in May 2018.
2,761
Hit-and-Run Crashes — May 2018
▲ 76.6% vs prior (1,563)
The count of hit-and-run crashes increased by 76.65%, from 1,563 in May 2017 to 2,761 in May 2018. Despite this increase in raw numbers, the overall hit-and-run rate as a percentage of total crashes slightly decreased from 26.7% to 25.8%.
Vulnerable Road User Casualties
2
Pedestrians Killed
0
Cyclists Killed
4
Motorists Killed
1
Other Killed
253
Pedestrians Injured
154
Cyclists Injured
1,746
Motorists Injured
1
Other Injured
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-05-01 to 2018-05-31 · 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 May 2017 (968 crashes) to Thursday in May 2018 (1,847 crashes). The peak hour remained consistent at 4 PM in both periods, with 525 crashes in May 2017 and 894 crashes in May 2018. All days of the week showed a substantial increase in crash counts, with Thursday experiencing the largest percentage increase of 127.04%.
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-05-01 to 2018-05-31 · Crash date field aggregated by weekday
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-05-01 to 2018-05-31 · Crash time field aggregated by hour (0-23)
Crash Severity Breakdown
The number of fatal crashes increased from 3 in May 2017 to 7 in May 2018, with the fatal crash rate per total crashes rising from 0.05% to 0.07%. The proportion of crashes resulting in no injury decreased from 91.6% to 84.8% year-over-year. Conversely, the combined proportion of serious, minor, and possible injury crashes increased from 8.2% to 14.9%.
Outcome by Severity (Crash Events)
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-05-01 to 2018-05-31 · KABCO injury classification scale
Severity Distribution
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-05-01 to 2018-05-31 · Most severe injury per crash record
Top Contributing Factors
The leading contributing factor, 'FAILING TO YIELD RIGHT-OF-WAY,' increased from 667 crashes in May 2017 to 1,241 crashes in May 2018, an 85.91% increase in count. 'FAILING TO REDUCE SPEED TO AVOID CRASH' saw a 206.06% increase in count, rising from 165 to 505 incidents. 'UNDER THE INFLUENCE OF ALCOHOL/DRUGS' incidents also increased by 200%, from 16 to 48.
Officer-Reported Primary Contributing Cause
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-05-01 to 2018-05-31 · Officer-reported primary contributory cause per crash
Road & Environmental Conditions
Crashes occurring in clear weather conditions increased by 87.04% in count, from 4,730 in May 2017 to 8,847 in May 2018, while those on dry road surfaces increased by 88.31% in count, from 4,584 to 8,632. Crashes during daylight hours rose by 82.59% in count, from 4,441 to 8,109. The proportion of crashes occurring in wet road conditions slightly decreased from 14.83% to 13.15% of total crashes.
Weather
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-05-01 to 2018-05-31 · Weather condition at time of crash
Lighting
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-05-01 to 2018-05-31 · Lighting condition field
Road Surface
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-05-01 to 2018-05-31 · Road surface condition field
Vehicles & Demographics
The total number of vehicles involved in crashes increased by 85.58%, from 11,751 to 21,808. There was a notable 245.88% increase in pedestrian involvement, from 85 to 294, and a 307.41% increase in bicycle involvement, from 54 to 220. All age groups saw increases in persons involved, with the 0-15 age group experiencing the largest percentage increase of 144.42%.
Top Vehicle Makes (21,808 vehicles)
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-05-01 to 2018-05-31 · Vehicle unit records
6,848 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 (24,241 persons with recorded sex)
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-05-01 to 2018-05-31 · Person-level records linked to crash events
Speed Limit Zones
Crashes occurring in 30 mph speed zones increased by 83.05% in count, from 4,377 in May 2017 to 8,012 in May 2018. The fatal rate within 30 mph zones increased from 0.069% to 0.087% year-over-year. Crashes in 25 mph zones also rose by 93.07% in count, from 303 to 585.
Fatal crashes by zone: 30 mph: 7 of 8,012 (0.087%)
Source: Chicago Traffic Crashes · Socrata Open Data · 2018-05-01 to 2018-05-31 · 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: 2018-05-01 through 2018-05-31
- Report generated: June 1, 2026
Data Coverage
- Reporting period: 2018-05-01 through 2018-05-31 (31 days)
- Geographic scope: Chicago, IL
- Total crash records analyzed: 10,714
- Total persons involved: 24,584
- Total vehicles involved: 21,808
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/may-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: 2018-05-01 – 2018-05-31
Generated: June 1, 2026 · All rights reserved