What the Data Shows

Sioux County, Iowa recorded 31 total road fatalities across 29 reported crashes during the 2016-2023 reporting window, according to NHTSA's Fatality Analysis Reporting System. The most recent year covered by the data logged 6 deaths on county roads, and the annual average works out to approximately 3.4 fatalities per year. Adjusted for population, the fatality rate is 9.4 per 100,000 residents, which leaves it safer than most U.S. counties by that per-capita measure among the 3,137 U.S. counties in this dataset.

Cause-code breakdowns are not individually published for Sioux County in the current FARS release, so readers looking for contributing-factor data should use the Iowa state page, which aggregates county-level case files into statewide totals. Either way, the underlying records are drawn from a census of fatal crashes, not a statistical sample, so the counts are actual deaths rather than estimates.

The directional trend for Sioux County is increasing, which means annual fatalities have risen across the reporting period and may warrant closer attention from local transportation and enforcement agencies. Residents, insurers, and policy analysts can use this baseline alongside population density, highway mile data, and rural-versus-urban road mix to judge whether Sioux County's 31-death total is proportionate to its exposure. All numbers are for research and informational use only.