Monthly Traffic Safety Analysis

4,622 CRASHES IN
IOWA, IA
DECEMBER 2020

All metrics benchmarked againstDecember 2019

In December 2020, Iowa recorded 4,622 total crashes, a 10.2% decrease from the 5,145 crashes reported in December 2019. Despite the overall decline in collisions and a 21.5% drop in injuries, the number of fatalities increased significantly. Total fatalities rose by 32.1% from 28 to 37 year-over-year, marking the most notable shift in the data.

4,622

▼ -10.2%was 5,145

Total Crash Events

37

▲ 32.1%was 28

Persons Killed

1,201

▼ -21.5%was 1,529

Persons Injured

29

▲ 7.4%was 27

Fatal Crash Events

Note: "Persons Killed" (37) counts individual fatalities across all crash events. "Fatal" in the severity table below (29) counts crash events where at least one fatality occurred. A single crash can result in multiple fatalities.

Source: Iowa Crash Data · ArcGIS Open Data · 2020-12-01 to 2020-12-31 · Aggregate counts from crash, person, and vehicle records

Trend Summary

Traffic safety data for December 2020 indicates a downward trend in the overall volume of crashes compared to the previous year. Total crashes fell by 10.2% from 5,145 to 4,622, and the number of people injured decreased by 21.5% from 1,529 to 1,201. In contrast to this trend, fatalities rose by 32.1%, increasing from 28 in December 2019 to 37 in December 2020.

Vulnerable Road User Casualties

1

Pedestrians Killed

Prior: 1→0.0%

2

Cyclists Killed

Prior: 0→%

34

Motorists Killed

Prior: 27↑25.9%

0

Other Killed

Prior: 0→0.0%

30

Pedestrians Injured

Prior: 34↓-11.8%

6

Cyclists Injured

Prior: 9↓-33.3%

1,162

Motorists Injured

Prior: 1,483↓-21.6%

3

Other Injured

Prior: 3→0.0%

Source: Iowa Crash Data · ArcGIS Open Data · 2020-12-01 to 2020-12-31 · 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 slightly year-over-year. The peak day for collisions moved from Monday (1,067 crashes) in December 2019 to Wednesday (802 crashes) in December 2020. The 5 p.m. hour remained the consistent peak time for crashes in both periods, accounting for 596 incidents in the prior year and 540 in the current period.

Source: Iowa Crash Data · ArcGIS Open Data · 2020-12-01 to 2020-12-31 · Crash date field aggregated by weekday

Source: Iowa Crash Data · ArcGIS Open Data · 2020-12-01 to 2020-12-31 · Crash time field aggregated by hour (0-23)

Crash Severity Breakdown

While overall crashes decreased, their severity profile worsened in December 2020 compared to the prior year. The number of fatal crashes increased from 27 to 29, and their corresponding share of all crashes rose from 0.5% to 0.6%. In contrast, crashes resulting in serious injuries declined in both count (from 94 to 63) and proportion (from 1.8% to 1.4% of total crashes). The share of crashes involving no injuries increased from 73.9% to 75.6%.

Severity is per crash event (most severe injury). 29 fatal crash events resulted in 37 persons killed.

Outcome by Severity (Crash Events)

Fatal29fatal crashes0.6%
↑7.4%prior 27
Serious Injury63serious injury crashes1.4%
↓-33.0%prior 94
Minor Injury348minor injury crashes7.5%
↓-15.9%prior 414
Possible Injury686possible injury crashes14.8%
↓-14.9%prior 806
No Injury3,496no injury crashes75.6%
↓-8.1%prior 3,804

Source: Iowa Crash Data · ArcGIS Open Data · 2020-12-01 to 2020-12-31 · KABCO injury classification scale

Severity Distribution (Crash Events)

Source: Iowa Crash Data · ArcGIS Open Data · 2020-12-01 to 2020-12-31 · Most severe injury per crash record

Top Contributing Factors

Collisions with animals remained the leading contributing factor in both periods, though the count of such incidents decreased from 802 to 771. The number of crashes attributed to 'Driving too fast for conditions' was unchanged at 415, elevating its rank from third to second place. A significant year-over-year change was the 34.7% drop in crashes from 'Followed too close,' which fell from 475 incidents to 310, moving it from the second to the fourth-ranked cause.

Officer-Reported Primary Contributing Cause

Animal771 (16.7%)↓-3.9%prior 802
Driving too fast for conditions415 (9%)→0.0%prior 415
Ran off road - left373 (8.1%)↓-2.1%prior 381
Followed too close310 (6.7%)↓-34.7%prior 475
Lost Control285 (6.2%)↓-1.0%prior 288
Other (explain in narrative): Other230 (5%)↓-23.8%prior 302
FTYROW: From stop sign196 (4.2%)↓-17.3%prior 237
Ran off road - straight175 (3.8%)↓-2.2%prior 179
Ran Traffic Signal172 (3.7%)↓-3.9%prior 179
FTYROW: Making left turn155 (3.4%)↓-17.6%prior 188

Source: Iowa Crash Data · ArcGIS Open Data · 2020-12-01 to 2020-12-31 · Officer-reported primary contributory cause per crash

Road & Environmental Conditions

The conditions under which crashes occurred showed a shift toward more adverse weather and road surfaces. The proportion of crashes on dry roads decreased from 57.8% in December 2019 to 51.8% in December 2020. Correspondingly, the share of crashes occurring on snowy roads increased from 9.2% to 14.2%. Lighting conditions remained relatively stable, with daylight crashes accounting for 46.0% of incidents in the current period versus 47.2% in the prior period.

Weather

Clear2,381 (60.0%)
↓-18.3%prior 2,916
Cloudy691 (17.4%)
↓-13.7%prior 801
Snow450 (11.3%)
↑13.6%prior 396
Freezing rain/drizzle139 (3.5%)
↑39.0%prior 100
Blowing Snow134 (3.4%)
↑54.0%prior 87
Rain86 (2.2%)
↓-20.4%prior 108
Fog, smoke, smog38 (1.0%)
↑8.6%prior 35
Severe Winds26 (0.7%)
↑333.3%prior 6
Other (explain in narrative)13 (0.3%)
↓-23.5%prior 17
Sleet, hail11 (0.3%)

Source: Iowa Crash Data · ArcGIS Open Data · 2020-12-01 to 2020-12-31 · Weather condition at time of crash

Lighting

Daylight2,127 (53.4%)
↓-12.4%prior 2,427
Dark - roadway lighted961 (24.1%)
↓-13.3%prior 1,109
Dark - roadway not lighted647 (16.2%)
↓-3.3%prior 669
Dusk141 (3.5%)
↑1.4%prior 139
Dawn76 (1.9%)
↓-38.7%prior 124
Dark - unknown roadway lighting30 (0.8%)
↑20.0%prior 25

Source: Iowa Crash Data · ArcGIS Open Data · 2020-12-01 to 2020-12-31 · Lighting condition field

Road Surface

Dry2,394 (60.2%)
↓-19.4%prior 2,972
Snow655 (16.5%)
↑37.9%prior 475
Ice/frost431 (10.8%)
↓-6.7%prior 462
Wet340 (8.6%)
↓-26.1%prior 460
Slush91 (2.3%)
↑139.5%prior 38
Gravel50 (1.3%)
↓-9.1%prior 55
Other (explain in narrative)10 (0.3%)
→0.0%prior 10
Mud, dirt3 (0.1%)
↓-62.5%prior 8

Source: Iowa Crash Data · ArcGIS Open Data · 2020-12-01 to 2020-12-31 · Road surface condition field

Vehicles & Demographics

The top vehicle makes involved in crashes were consistent across both periods, with Ford, Chev, and Chevrolet holding the top three ranks in both years, though their incident counts decreased. Demographically, the number of persons involved in crashes fell across all age groups, in line with the overall reduction in collisions. The 26-34 age group remained the largest cohort of individuals involved in crashes in both December 2019 and December 2020.

Top Vehicle Makes (7,555 vehicles)

1
FORD1,254 (16.6%)
↓-10.2%prior 1,396
2
CHEV959 (12.7%)
↓-17.6%prior 1,164
3
CHEVROLET572 (7.6%)
↑3.1%prior 555
4
TOYT294 (3.9%)
↓-30.8%prior 425
5
JEEP288 (3.8%)
↓-10.3%prior 321
6
DODG276 (3.7%)
↓-14.3%prior 322
7
GMC267 (3.5%)
↓-1.5%prior 271
8
NR250 (3.3%)
↑0.4%prior 249
9
DODGE233 (3.1%)
↑16.5%prior 200
10
TOYOTA217 (2.9%)
↓-5.2%prior 229

Source: Iowa Crash Data · ArcGIS Open Data · 2020-12-01 to 2020-12-31 · Vehicle unit records

1,455 persons with unknown or unrecorded age excluded from age chart.

Sex Distribution (6,690 persons with recorded sex)

Male3,963 (59.2%)
↓-9.0%prior 4,357
Female2,727 (40.8%)
↓-21.7%prior 3,483

Source: Iowa Crash Data · ArcGIS Open Data · 2020-12-01 to 2020-12-31 · 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: 2020-12-01 through 2020-12-31
  • Report generated: September 9, 2026

Data Coverage

  • Reporting period: 2020-12-01 through 2020-12-31 (31 days)
  • Geographic scope: iowa, IA
  • Total crash records analyzed: 4,622
  • Total persons involved: 10,147
  • Total vehicles involved: 7,555

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: December 2020." Published September 9, 2026. Reporting period: 2020-12-01 to 2020-12-31. Data source: Iowa Crash Data, ArcGIS Open Data. Available at: https://thatcarhitme.com/crash-data/iowa/statewide/december-2020-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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