States › Colorado › Jefferson County
Jefferson County
Residents 578,533Deaths 2024 54Deaths 2015–2024 478Latest 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.
Jefferson County, Colorado, recorded 54 deaths in 52 fatal crashes in 2024, the latest FARS data year, and 478 deaths in 450 fatal crashes over 2015–2024.
With 578,533 residents, that is 8.3 deaths per 100,000 people a year over the ten years, 27% lower than the Colorado rate of 11.4 and below the national rate of 11.8.
The ten-year death toll rose 25% from 382 in 2005–2014 to 478 in 2015–2024.
Of the factors FARS records, the one that stands furthest above the state share here is motorcyclists: 29.1% against 19.4% for Colorado.
38% of the county's fatal crashes happened between 6pm to midnight, and Sunday was the most common day (20%).
Trend since 1975
Ten-year total up 25% (382 in 2005–2014, 478 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 Colorado and the nation
| Measure | Jefferson | Colorado | United States |
|---|---|---|---|
| Deaths per 100,000 residents a year, 2015–2024 | 8.3 | 11.4 | 11.8 |
| Deaths per 100,000 residents, 2024 | 9.3 | 11.6 | 11.5 |
| Deaths, 2015–2024 | 478 | 6,518 | 389,190 |
| Fatal crashes, 2015–2024 | 450 | 6,017 | 358,460 |
| Deaths per fatal crash | 1.1 | 1.1 | 1.1 |
| Change vs previous ten years | +25% | +29% | +7% |
| Crashes on rural roads | 18% | 39% | 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 578,533 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 Jefferson County by weekday and hour, 2015–2024: darker cells are busier. 450 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 Colorado 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 Jefferson
| # | Route | Type | In county | Fatal crashes | Deaths | Alcohol | Speeding |
|---|---|---|---|---|---|---|---|
| 1 | State Route 121 | State highway | 56 | 62 | 64 | 34% | 36% |
| 2 | US Route 6 | US highway | 42 | 109 | 117 | 36% | 29% |
| 3 | Interstate 70 | Interstate | 35 | 313 | 352 | 29% | 30% |
| 4 | US Route 40 | US highway | 30 | 176 | 194 | 29% | 34% |
| 5 | State Route 391 | State highway | 28 | 28 | 29 | 21% | 32% |
| 6 | US Route 285 | US highway | 26 | 103 | 111 | 25% | 30% |
| 7 | State Route 95 | State highway | 16 | 49 | 51 | 37% | 22% |
| 8 | State Route 72 | State highway | 12 | 20 | 23 | 25% | 40% |
| 9 | State Route 470 | State highway | 11 | 41 | 43 | 34% | 27% |
| 10 | US Route 36 | US highway | 4 | 56 | 61 | 39% | 36% |
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 | 52 | 54 | 15 | 9.3 | CO 2024 |
| 2023 | 47 | 47 | 17 | 8.1 | CO 2023 |
| 2022 | 49 | 49 | 21 | 8.5 | CO 2022 |
| 2021 | 50 | 52 | 21 | 9.0 | CO 2021 |
| 2020 | 41 | 43 | 12 | 7.4 | CO 2020 |
| 2019 | 45 | 51 | 10 | 8.8 | CO 2019 |
| 2018 | 36 | 38 | 14 | 6.6 | CO 2018 |
| 2017 | 35 | 41 | 10 | 7.1 | CO 2017 |
| 2016 | 45 | 48 | 12 | 8.3 | CO 2016 |
| 2015 | 50 | 55 | 22 | 9.5 | CO 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 Jefferson County, Colorado?
54 people died in 52 fatal crashes in 2024; 245 over 2020–2024 and 478 over 2015–2024, according to NHTSA's Fatality Analysis Reporting System.
How does Jefferson compare with Colorado?
8.3 deaths per 100,000 residents a year over 2015–2024, against 11.4 for Colorado and 11.8 nationally. Rates use Census Bureau population estimates.
What share of fatal crashes in Jefferson involved alcohol?
34.2% of fatal crashes in 2015–2024 had at least one driver reported by police as drinking, against 34.1% in Colorado. The factor furthest above the state share was motorcyclists at 29.1%.
Which roads in Jefferson see the most fatal crashes?
Among signed routes with a page on this site, State Route 121 (56 fatal crashes in the county, 2015–2024), US Route 6 (42 fatal crashes in the county, 2015–2024) and Interstate 70 (35 fatal crashes in the county, 2015–2024).
When do fatal crashes happen in Jefferson?
Most often between 6pm to midnight (38% of crashes) and on Sundays (20%); 46.2% 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.