Ada County
Residents 535,799Deaths 2024 29Deaths 2015–2024 259Latest data year 2024
FARS data are based on police crash reports and other sources; the drunk-driving measure is based on the highest BAC of any driver in the crash. Latest data year: 2024. Figures are aggregates from NHTSA's Fatality Analysis Reporting System; no individual crash is identified.
NHTSA's FARS file lists 259 people killed in 240 fatal crashes in Ada County, Idaho, between 2015 and 2024, 29 of them in 2024.
With 535,799 residents, that is 5.3 deaths per 100,000 people a year over the ten years, 60% lower than the Idaho rate of 13.1 and below the national rate of 11.8.
The ten-year death toll rose 37% from 189 in 2005–2014 to 259 in 2015–2024.
Of the factors FARS records, the one that stands furthest above the state share here is pedestrians: 18.9% against 6.9% for Idaho.
33% of the county's fatal crashes happened between 6pm to midnight, and Tuesday was the most common day (15%).
Trend since 1975
Ten-year total up 37% (189 in 2005–2014, 259 in 2015–2024). The shaded band is the ten-year window used for rates and shares. County codes are matched to today's Census county list; a few historic code changes are merged.
Compared with Idaho and the nation
| Measure | Ada | Idaho | United States |
|---|---|---|---|
| Deaths per 100,000 residents a year, 2015–2024 | 5.3 | 13.1 | 11.8 |
| Deaths per 100,000 residents, 2024 | 5.4 | 11.9 | 11.5 |
| Deaths, 2015–2024 | 259 | 2,387 | 389,190 |
| Fatal crashes, 2015–2024 | 240 | 2,159 | 358,460 |
| Deaths per fatal crash | 1.1 | 1.1 | 1.1 |
| Change vs previous ten years | +37% | +8% | +7% |
| Crashes on rural roads | 25% | 75% | 43% |
Rates divide deaths by Census Bureau population estimates for each year (residents, not road users; through traffic on major routes raises the rate of small counties). Population 535,799 in 2024.
Factors
"Alcohol" counts crashes where police reported at least one driver as drinking (FARS DR_DRINK), not the BAC-based alcohol-impaired measure NHTSA publishes separately. "Speeding" counts crashes with a driver coded as racing, exceeding the limit or too fast for conditions. Details in the methodology. Factor pages: alcohol, speeding, pedestrians, motorcycles, unrestrained occupants.
Time of day and day of week
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Fatal crashes in Ada County by weekday and hour, 2015–2024: darker cells are busier. 240 crashes with a known hour and weekday.
By weekday
Light condition
Road type
FHWA functional classes as coded in FARS (FUNC_SYS), share of fatal crashes with a reported class; tick marks the Idaho share. Interstates and other principal arterials carry the most traffic, so a high share there is expected. See what the road classes mean.
Weather
Routes with the most fatal crashes in Ada
| # | Route | Type | In county | Fatal crashes | Deaths | Alcohol | Speeding |
|---|---|---|---|---|---|---|---|
| 1 | Interstate 84 | Interstate | 43 | 200 | 217 | 21% | 21% |
| 2 | US Route 20 | US highway | 14 | 100 | 117 | 20% | 16% |
| 3 | State Route 21 | State highway | 11 | 27 | 29 | 33% | 48% |
| 4 | State Route 55 | State highway | 10 | 65 | 70 | 17% | 12% |
| 5 | US Route 26 | US highway | 1 | 40 | 44 | 23% | 18% |
Signed routes (Interstate, US and state highways) that have a page on this site, ranked by fatal crashes in this county over 2015–2024; "fatal crashes" and "deaths" columns are the statewide totals for the route. Local streets and county roads are not listed.
By year, 2015–2024
| Year | Fatal crashes | Deaths | Drinking-driver crashes | Per 100,000 | |
|---|---|---|---|---|---|
| 2024 | 29 | 29 | 12 | 5.4 | ID 2024 |
| 2023 | 31 | 31 | 7 | 5.8 | ID 2023 |
| 2022 | 19 | 21 | 9 | 3.9 | ID 2022 |
| 2021 | 21 | 21 | 7 | 3.9 | ID 2021 |
| 2020 | 17 | 20 | 7 | 3.7 | ID 2020 |
| 2019 | 21 | 29 | 9 | 5.4 | ID 2019 |
| 2018 | 28 | 31 | 7 | 5.8 | ID 2018 |
| 2017 | 29 | 30 | 8 | 5.6 | ID 2017 |
| 2016 | 23 | 24 | 6 | 4.5 | ID 2016 |
| 2015 | 22 | 23 | 10 | 4.3 | ID 2015 |
Counts under three are shown as "1–2" (small-count rule). Per-100,000 uses the 2024 population for every year in this table; the ten-year rate above uses each year's estimate.
Questions and answers
How many people died in crashes in Ada County, Idaho?
29 people died in 29 fatal crashes in 2024; 122 over 2020–2024 and 259 over 2015–2024, according to NHTSA's Fatality Analysis Reporting System.
How does Ada compare with Idaho?
5.3 deaths per 100,000 residents a year over 2015–2024, against 13.1 for Idaho and 11.8 nationally. Rates use Census Bureau population estimates.
What share of fatal crashes in Ada involved alcohol?
34.2% of fatal crashes in 2015–2024 had at least one driver reported by police as drinking, against 31.2% in Idaho. The factor furthest above the state share was pedestrians at 18.9%.
Which roads in Ada see the most fatal crashes?
Among signed routes with a page on this site, Interstate 84 (43 fatal crashes in the county, 2015–2024), US Route 20 (14 fatal crashes in the county, 2015–2024) and State Route 21 (11 fatal crashes in the county, 2015–2024).
When do fatal crashes happen in Ada?
Most often between 6pm to midnight (33% of crashes) and on Tuesdays (15%); 45.4% happened after dark.
Where does this data come from?
NHTSA's Fatality Analysis Reporting System annual files (1975–2024) and Census Bureau county population estimates. Figures are aggregates; no individual crash is identified. See the methodology page for definitions.
Provenance
Source: National Highway Traffic Safety Administration, Fatality Analysis Reporting System, annual national CSV files 1975–2024 (accident table for every year; vehicle and person tables for 2015–2024), public domain. Population: US Census Bureau, Population Estimates Program, county totals (vintages 2000–2010, 2010–2020 and 2020–2024). Data through 31 Dec 2024; page generated 30 Sep 2026. Processing errors are corrected at the next build; see corrections and sources.