Guidesfrom NHTSA FARS
What Does a Fatal Crash Rate per 100,000 Mean?
A fatal crash rate per 100,000 is NHTSA fatal crashes divided by Census population, times 100,000. The math on a real county, and why small counties swing.
The short answer
A fatal crash rate per 100,000 is the number of fatal crashes recorded in a place in one year, divided by the number of people who live there, times 100,000. It answers one question: if this place had exactly 100,000 residents and fatal crashes happened at the same pace, how many would there be? It lets you read a county of 5,000 and a county of 5 million on one scale.
fatal crashes ÷ residents × 100,000 = fatal crash rate per 100,000
The crashes come from NHTSA’s Fatality Analysis Reporting System, which records every crash on a public road in which someone died within 30 days. The residents come from the Census Bureau’s July 1 population estimate for the same year.
A worked example
In 2024, FARS recorded 551 fatal crashes in Harris County, Texas, in which 583 people died. The Census Bureau estimates 4,996,331 people lived there that year.
551 ÷ 4,996,331 × 100,000 = 11.0
So the fatal crash rate is 11.0 per 100,000 residents. The United States as a whole was 10.7 that year (36,297 fatal crashes among 340,003,797 people). Both numbers sit on the county page, with the inputs, so the comparison is never two bare figures.
Why multiply by 100,000?
Dividing crashes by population gives a tiny decimal that is hard to read. Multiplying by 100,000 turns it into a scale with whole numbers. It is a scale, not a count: a rate of 11.0 does not mean 11.0 crashes happened. Federal highway safety rules use the same convention for fatalities per 100,000 people, and the same rules define the per-mile form that state pages add.
Crashes, not deaths
The rate here counts crashes. One crash can kill more than one person, so the number of deaths is always a little higher and is printed beside the rate. In Harris County in 2024, the 551 crashes killed 583 people. Many published figures use deaths instead, so check which one you are reading before comparing.
Small counties swing a lot
A rate is steady when the counts behind it are large and jumpy when they are small. Loving County, Texas has fewer than 100 residents, so every fatal crash moves its rate by thousands of points.
| Year | Fatal crashes | Residents | Rate per 100,000 |
|---|---|---|---|
| 2020 | 2 | 63 | 3174.6 |
| 2021 | 2 | 57 | 3508.8 |
| 2022 | 4 | 46 | 8695.7 |
| 2023 | 3 | 46 | 6521.7 |
| 2024 | 1 | 47 | 2127.7 |
None of those rates says anything about how dangerous the roads are for the people who live there. A county that small sits on a highway that carries far more drivers than residents, and one crash is enough to double the number. That is why every county page prints the population beside the rate, and why the site shows a five-year average: Loving County’s is 4633.2 over 2020 to 2024, and Harris County’s is 10.7. It is also why CrashRate never ranks counties.
What the rate leaves out
- Crashes where nobody died. FARS records fatal crashes only. Injury crashes and property damage sit in separate state files and are not counted here.
- People who are not residents. Population counts the people who live in a county. Commuters, truckers and visitors add crashes without adding residents, which pushes a rate up on a through-route county and down on a bedroom county.
- Your own risk. It describes a whole county over a whole year. It is not the chance that something happens to one driver, on one road, on one trip.
- Why two places differ. Road type, speed limits, miles driven, weather and the mix of rural and urban roads all shape a count. The rate does not separate them. The county page lists what FARS does record about each crash.
What this guide does not cover
It does not cover the per-mile rate, which has its own guide, or how FARS decides what is a fatal crash, which has another. It does not say whether any rate is high or low. That depends on what you compare it with, and the comparison has limits of its own.
Look up a county
The Fatal Crash Rate lookup shows this math for any US county: the fatal crashes, the deaths, the population, the rate, the five-year average, and every year back to 2020.
Sources
This guide is for informational purposes only and is not professional advice. A fatal crash rate describes fatal crashes recorded in one place over one year. It is not all crashes, not injuries, and not the risk to any one driver, road or trip.
Last reviewed: October 2026 · Against the FARS 2024 Annual Report File and Census Vintage 2025 estimates.