ThatCarHitMe.com
An Injuria.ai Company
YEAR-OVER-YEAR CRASH REPORT · IOWA, IA · SEPTEMBER 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/iowa/statewide/september-2018-report
Monthly Traffic Safety Analysis
4,607 CRASHES IN
IOWA, IA
SEPTEMBER 2018
In September 2018, there were 4,607 total crashes, a marginal decrease of 0.5% from the 4,630 crashes recorded in September 2017. While the overall number of crashes remained stable, the most notable year-over-year shift was a significant reduction in crash severity. The number of fatalities dropped by 44.4%, from 45 in the prior period to 25 in the current period.
4,607
▼ -0.5%was 4,630
Total Crash Events
25
▼ -44.4%was 45
Persons Killed
1,612
▼ -8.9%was 1,770
Persons Injured
21
▼ -47.5%was 40
Fatal Crash Events
Note: "Persons Killed" (25) counts individual fatalities across all crash events. "Fatal" in the severity table below (21) counts crash events where at least one fatality occurred. A single crash can result in multiple fatalities.
Source: Iowa Crash Data · ArcGIS Open Data · 2018-09-01 to 2018-09-30 · Aggregate counts from crash, person, and vehicle records
Trend Summary
Year-over-year crash totals were largely stable, decreasing by only 23 incidents from 4,630 in September 2017 to 4,607 in September 2018. However, the outcomes of these crashes improved significantly. Total fatalities fell from 45 to 25, a 44.4% decrease, and total injuries declined from 1,770 to 1,612, a reduction of 8.9%.
Vulnerable Road User Casualties
3
Pedestrians Killed
1
Cyclists Killed
21
Motorists Killed
0
Other Killed
35
Pedestrians Injured
46
Cyclists Injured
1,526
Motorists Injured
5
Other Injured
Source: Iowa Crash Data · ArcGIS Open Data · 2018-09-01 to 2018-09-30 · Mode classified from person records (driver/passenger → motorist; pedestrian; bicyclist → cyclist; in-line skater / unspecified → other)
When Crashes Happen
The temporal patterns of crashes remained consistent year-over-year. Friday was the peak day for crashes in both September 2018 (778 crashes) and September 2017 (960 crashes), though the volume of crashes on the peak day decreased. Similarly, the 3 p.m. hour was the peak hour in both periods, with 379 crashes in the current period and 396 in the prior period. The overall distribution of crashes by day of the week and hour of the day showed no major shifts.
Source: Iowa Crash Data · ArcGIS Open Data · 2018-09-01 to 2018-09-30 · Crash date field aggregated by weekday
Source: Iowa Crash Data · ArcGIS Open Data · 2018-09-01 to 2018-09-30 · Crash time field aggregated by hour (0-23)
Crash Severity Breakdown
There was a notable shift towards less severe crashes in September 2018 compared to the previous year. The number of fatal crashes decreased from 40 to 21, and their share of all crashes fell from 0.9% to 0.5%. Crashes resulting in serious injuries also decreased in both count (from 150 to 104) and proportion (from 3.2% to 2.3%). Consequently, the share of crashes with no reported injuries increased from 67.5% in the prior period to 70.3% in the current period.
Severity is per crash event (most severe injury). 21 fatal crash events resulted in 25 persons killed.
Outcome by Severity (Crash Events)
Source: Iowa Crash Data · ArcGIS Open Data · 2018-09-01 to 2018-09-30 · KABCO injury classification scale
Severity Distribution (Crash Events)
Source: Iowa Crash Data · ArcGIS Open Data · 2018-09-01 to 2018-09-30 · Most severe injury per crash record
Top Contributing Factors
The ranking of top contributing factors shifted between September 2017 and September 2018. Collisions involving an animal became the leading factor, with the count of such incidents increasing by 39.8% from 422 to 590. 'Followed too close,' the top factor in the prior year with 602 crashes, decreased by 7.0% to 560 crashes, making it the second-leading factor in the current period. Crashes attributed to 'Lost Control' saw a notable decrease in count from 272 to 221.
Officer-Reported Primary Contributing Cause
Source: Iowa Crash Data · ArcGIS Open Data · 2018-09-01 to 2018-09-30 · Officer-reported primary contributory cause per crash
Road & Environmental Conditions
Driving conditions differed significantly between the two periods, with a notable increase in crashes occurring in adverse weather. Crashes on wet road surfaces more than tripled, rising from 250 in September 2017 to 788 in September 2018, and their share of total crashes increased from 5.4% to 17.1%. Correspondingly, crashes in rainy conditions increased from 151 to 511. Crashes during daylight and on dry roads decreased in both count and proportion compared to the prior year.
Weather
Source: Iowa Crash Data · ArcGIS Open Data · 2018-09-01 to 2018-09-30 · Weather condition at time of crash
Lighting
Source: Iowa Crash Data · ArcGIS Open Data · 2018-09-01 to 2018-09-30 · Lighting condition field
Road Surface
Source: Iowa Crash Data · ArcGIS Open Data · 2018-09-01 to 2018-09-30 · Road surface condition field
Vehicles & Demographics
The distribution of persons involved in crashes by age group remained largely consistent year-over-year, with only minor fluctuations such as a slight increase in the 26-34 and 65+ age groups. The ranking of the most common vehicle makes involved in crashes was also stable. Ford and Chevrolet (listed as 'CHEV' and 'CHEVROLET') were the top two makes in both periods, with their respective crash counts remaining similar. The top five makes, including Toyota, Dodge, and Honda, maintained their high rankings across both years.
Top Vehicle Makes (8,062 vehicles)
Source: Iowa Crash Data · ArcGIS Open Data · 2018-09-01 to 2018-09-30 · Vehicle unit records
1,011 persons with unknown or unrecorded age excluded from age chart.
Sex Distribution (5,822 persons with recorded sex)
Source: Iowa Crash Data · ArcGIS Open Data · 2018-09-01 to 2018-09-30 · Person-level records linked to crash events
Data Sources & Methodology
Primary Data Source
All crash data in this report is sourced from Iowa Crash Data, accessed programmatically via the ArcGIS 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: ArcGIS 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: 2018-09-01 through 2018-09-30
- Report generated: September 9, 2026
Data Coverage
- Reporting period: 2018-09-01 through 2018-09-30 (30 days)
- Geographic scope: iowa, IA
- Total crash records analyzed: 4,607
- Total persons involved: 9,006
- Total vehicles involved: 8,062
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). "iowa, IA Crash Intelligence Report: September 2018." Published September 9, 2026. Reporting period: 2018-09-01 to 2018-09-30. Data source: Iowa Crash Data, ArcGIS Open Data. Available at: https://thatcarhitme.com/crash-data/iowa/statewide/september-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: Iowa Crash Data · ArcGIS
Period: 2018-09-01 – 2018-09-30
Generated: September 9, 2026 · All rights reserved