Yearly Traffic Safety Analysis

10,645 CRASHES IN
IOWA, IA
2018

All metrics benchmarked against2017

In 2018, Polk County recorded 10,645 crashes, a slight decrease from 10,648 crashes in 2017. While total fatalities saw a minor increase from 26 to 27, there was a notable 7.97% reduction in total injuries, decreasing from 3,950 in 2017 to 3,635 in 2018.

10,645

▼ -0.0%was 10,648

Total Crash Events

27

▲ 3.8%was 26

Persons Killed

3,635

▼ -8.0%was 3,950

Persons Injured

24

Fatal Crash Events

Note: "Persons Killed" (27) counts individual fatalities across all crash events. "Fatal" in the severity table below (24) counts crash events where at least one fatality occurred. A single crash can result in multiple fatalities.

Source: Iowa Crash Data · ArcGIS Open Data · 2018-01-01 to 2018-12-31 · Aggregate counts from crash, person, and vehicle records

Trend Summary

Overall crash numbers in Polk County remained stable year-over-year, with a negligible decrease of 3 crashes, from 10,648 in 2017 to 10,645 in 2018. Fatalities increased slightly by 1, from 26 to 27, representing a 3.85% rise. Conversely, total injuries saw a significant decrease of 315, dropping from 3,950 to 3,635, a reduction of 7.97%.

Vulnerable Road User Casualties

3

Pedestrians Killed

Prior: 4↓-25.0%

1

Cyclists Killed

Prior: 1→0.0%

23

Motorists Killed

Prior: 21↑9.5%

0

Other Killed

Prior: 0→0.0%

92

Pedestrians Injured

Prior: 95↓-3.2%

67

Cyclists Injured

Prior: 61↑9.8%

3,467

Motorists Injured

Prior: 3,791↓-8.5%

9

Other Injured

Prior: 3↑200.0%

Source: Iowa Crash Data · ArcGIS Open Data · 2018-01-01 to 2018-12-31 · Mode classified from person records (driver/passenger → motorist; pedestrian; bicyclist → cyclist; in-line skater / unspecified → other)

When Crashes Happen

The peak day for crashes remained Friday in both years, though the number of crashes on Friday decreased from 1,920 in 2017 to 1,838 in 2018. The peak crash hour also remained 5p, with a slight reduction from 1,077 crashes in 2017 to 1,030 crashes in 2018. Notably, Monday crashes increased by 188 (from 1,474 to 1,662), while Sunday crashes decreased by 109 (from 1,095 to 986).

Source: Iowa Crash Data · ArcGIS Open Data · 2018-01-01 to 2018-12-31 · Crash date field aggregated by weekday

Source: Iowa Crash Data · ArcGIS Open Data · 2018-01-01 to 2018-12-31 · Crash time field aggregated by hour (0-23)

Crash Severity Breakdown

Fatal crashes remained stable at 24 in both years, maintaining a fatal crash rate of 0.23% in both periods. Serious injury crashes decreased from 156 in 2017 to 149 in 2018, and minor injury crashes also decreased from 920 to 863. Conversely, "No Injury" crashes increased from 7,130 in 2017 to 7,393 in 2018, suggesting a shift towards less severe outcomes.

Severity is per crash event (most severe injury). 24 fatal crash events resulted in 27 persons killed.

Outcome by Severity (Crash Events)

Fatal24fatal crashes0.2%
→0.0%prior 24
Serious Injury149serious injury crashes1.4%
↓-4.5%prior 156
Minor Injury863minor injury crashes8.1%
↓-6.2%prior 920
Possible Injury2,216possible injury crashes20.8%
↓-8.4%prior 2,418
No Injury7,393no injury crashes69.5%
↑3.7%prior 7,130

Source: Iowa Crash Data · ArcGIS Open Data · 2018-01-01 to 2018-12-31 · KABCO injury classification scale

Severity Distribution (Crash Events)

Source: Iowa Crash Data · ArcGIS Open Data · 2018-01-01 to 2018-12-31 · Most severe injury per crash record

Top Contributing Factors

Followed too close remained the leading contributing factor, increasing from 1,873 crashes in 2017 to 1,907 crashes in 2018. The most significant change was observed in "Driving too fast for conditions," which saw a substantial increase of 181 crashes, rising from 519 in 2017 to 700 in 2018, and moving from the sixth to the third most common factor. Conversely, "FTYROW: Making left turn" decreased by 67 crashes, from 724 to 657, shifting from the third to the fourth position.

Officer-Reported Primary Contributing Cause

Followed too close1,907 (17.9%)↑1.8%prior 1,873
Other (explain in narrative): Other754 (7.1%)↑1.1%prior 746
Driving too fast for conditions700 (6.6%)↑34.9%prior 519
FTYROW: Making left turn657 (6.2%)↓-9.3%prior 724
Ran Traffic Signal609 (5.7%)↓-1.0%prior 615
Ran off road - left539 (5.1%)↓-1.5%prior 547
FTYROW: From stop sign436 (4.1%)↓-12.4%prior 498
Operating vehicle in an reckless, erratic, careless, negligent manner411 (3.9%)↓-2.1%prior 420
Improper or erratic lane changing362 (3.4%)↑16.0%prior 312
Lost Control325 (3.1%)↓-5.8%prior 345

Source: Iowa Crash Data · ArcGIS Open Data · 2018-01-01 to 2018-12-31 · Officer-reported primary contributory cause per crash

Road & Environmental Conditions

Crashes occurring in 'Clear' weather decreased slightly from 6,604 to 6,550, while crashes in 'Rain' conditions increased from 685 to 791. A notable shift was observed in road surface conditions, with 'Dry' road crashes decreasing by 725 (from 8,337 to 7,612), while crashes on 'Wet' roads increased by 328 (from 1,421 to 1,749) and on 'Ice/frost' roads by 288 (from 206 to 494).

Weather

Clear6,550 (62.9%)
↓-0.8%prior 6,604
Cloudy2,466 (23.7%)
↓-5.2%prior 2,602
Rain791 (7.6%)
↑15.5%prior 685
Snow337 (3.2%)
↑16.6%prior 289
Freezing rain/drizzle171 (1.6%)
↑62.9%prior 105
Blowing Snow41 (0.4%)
↑70.8%prior 24
Fog, smoke, smog24 (0.2%)
↓-63.6%prior 66
Other (explain in narrative)12 (0.1%)
Sleet, hail11 (0.1%)
↑120.0%prior 5
Severe Winds9 (0.1%)
→0.0%prior 9

Source: Iowa Crash Data · ArcGIS Open Data · 2018-01-01 to 2018-12-31 · Weather condition at time of crash

Lighting

Daylight7,425 (71.1%)
↓-0.9%prior 7,489
Dark - roadway lighted2,093 (20.0%)
↑4.7%prior 1,999
Dark - roadway not lighted419 (4.0%)
↑1.5%prior 413
Dusk259 (2.5%)
↓-10.1%prior 288
Dawn222 (2.1%)
↓-4.3%prior 232
Dark - unknown roadway lighting30 (0.3%)
↑36.4%prior 22

Source: Iowa Crash Data · ArcGIS Open Data · 2018-01-01 to 2018-12-31 · Lighting condition field

Road Surface

Dry7,612 (73.1%)
↓-8.7%prior 8,337
Wet1,749 (16.8%)
↑23.1%prior 1,421
Ice/frost494 (4.7%)
↑139.8%prior 206
Snow445 (4.3%)
↑31.7%prior 338
Slush84 (0.8%)
↑42.4%prior 59
Gravel8 (0.1%)
↓-50.0%prior 16
Water (standing or moving)7 (0.1%)
Mud, dirt6 (0.1%)
→0.0%prior 6
Other (explain in narrative)3 (0.0%)
Sand2 (0.0%)
↓-66.7%prior 6

Source: Iowa Crash Data · ArcGIS Open Data · 2018-01-01 to 2018-12-31 · Road surface condition field

Vehicles & Demographics

Ford remained the most common vehicle make involved in crashes, increasing by 96 vehicles from 2,970 to 3,066. Honda vehicles saw a notable increase of 183 in crash involvement, rising from 842 to 1,025. In terms of age demographics, persons in the 35-44 age group involved in crashes increased by 141 (from 3,505 to 3,646), and those in the 55-64 age group increased by 114 (from 2,347 to 2,461).

Top Vehicle Makes (20,641 vehicles)

1
FORD3,066 (14.9%)
↑3.2%prior 2,970
2
CHEV2,761 (13.4%)
↑6.2%prior 2,601
3
TOYT1,251 (6.1%)
↑3.3%prior 1,211
4
HOND1,025 (5%)
↑21.7%prior 842
5
CHEVROLET920 (4.5%)
↓-24.9%prior 1,225
6
DODG889 (4.3%)
↑2.9%prior 864
7
NR820 (4%)
↑3.5%prior 792
8
NISS811 (3.9%)
↑15.5%prior 702
9
JEEP720 (3.5%)
↓-3.5%prior 746
10
KIA539 (2.6%)
↑16.4%prior 463

Source: Iowa Crash Data · ArcGIS Open Data · 2018-01-01 to 2018-12-31 · Vehicle unit records

3,339 persons with unknown or unrecorded age excluded from age chart.

Sex Distribution (16,889 persons with recorded sex)

Male9,274 (54.9%)
↑4.4%prior 8,884
Female7,615 (45.1%)
↑3.9%prior 7,329

Source: Iowa Crash Data · ArcGIS Open Data · 2018-01-01 to 2018-12-31 · 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: 2018-01-01 through 2018-12-31
  • Report generated: September 9, 2026

Data Coverage

  • Reporting period: 2018-01-01 through 2018-12-31 (365 days)
  • Geographic scope: iowa, IA
  • Total crash records analyzed: 10,645
  • Total persons involved: 24,273
  • Total vehicles involved: 20,641

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: 2018." Published September 9, 2026. Reporting period: 2018-01-01 to 2018-12-31. Data source: Iowa Crash Data, ArcGIS Open Data. Available at: https://thatcarhitme.com/crash-data/iowa/statewide/2018-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

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