States › South Dakota › Lyman County
Lyman County
Residents 3,721Deaths 2024 5Deaths 2015–2024 21Latest 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.
Lyman County, South Dakota, recorded 5 deaths in 4 fatal crashes in 2024, the latest FARS data year, and 21 deaths in 17 fatal crashes over 2015–2024.
With 3,721 residents, that is 55.5 deaths per 100,000 people a year over the ten years, about 3.7 times the South Dakota rate of 14.9 and above the national rate of 11.8.
The ten-year death toll fell 32% from 31 in 2005–2014 to 21 in 2015–2024.
Of the factors FARS records, the one that stands furthest above the state share here is speeding: 29.4% against 26.6% for South Dakota.
41% of the county's fatal crashes happened between 6pm to midnight, and Thursday was the most common day (29%).
Trend since 1975
Ten-year total down 32% (31 in 2005–2014, 21 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 South Dakota and the nation
| Measure | Lyman | South Dakota | United States |
|---|---|---|---|
| Deaths per 100,000 residents a year, 2015–2024 | 55.5 | 14.9 | 11.8 |
| Deaths per 100,000 residents, 2024 | 134.4 | 15.8 | 11.5 |
| Deaths, 2015–2024 | 21 | 1,323 | 389,190 |
| Fatal crashes, 2015–2024 | 17 | 1,174 | 358,460 |
| Deaths per fatal crash | 1.2 | 1.1 | 1.1 |
| Change vs previous ten years | -32% | -7% | +7% |
| Crashes on rural roads | 100% | 82% | 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 3,721 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
| 12am | 3am | 6am | 9am | 12pm | 3pm | 6pm | 9pm | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sun | ||||||||||||||||||||||||
| Mon | ||||||||||||||||||||||||
| Tue | ||||||||||||||||||||||||
| Wed | ||||||||||||||||||||||||
| Thu | ||||||||||||||||||||||||
| Fri | ||||||||||||||||||||||||
| Sat |
Fatal crashes in Lyman County by weekday and hour, 2015–2024: darker cells are busier. 17 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 South Dakota 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 Lyman
| # | Route | Type | In county | Fatal crashes | Deaths | Alcohol | Speeding |
|---|---|---|---|---|---|---|---|
| 1 | Interstate 90 | Interstate | 6 | 112 | 127 | 21% | 26% |
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 | 4 | 5 | 1–2 | 134.4 | SD 2024 |
| 2023 | 3 | 4 | 1–2 | 107.5 | SD 2023 |
| 2022 | 0 | 0 | 0 | — | SD 2022 |
| 2021 | 0 | 0 | 0 | — | SD 2021 |
| 2020 | 0 | 0 | 0 | — | SD 2020 |
| 2019 | 3 | 4 | 1–2 | 107.5 | SD 2019 |
| 2018 | 4 | 5 | 1–2 | 134.4 | SD 2018 |
| 2017 | 0 | 0 | 0 | — | SD 2017 |
| 2016 | 3 | 3 | 0 | 80.6 | SD 2016 |
| 2015 | 0 | 0 | 0 | — | SD 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 Lyman County, South Dakota?
5 people died in 4 fatal crashes in 2024; 9 over 2020–2024 and 21 over 2015–2024, according to NHTSA's Fatality Analysis Reporting System.
How does Lyman compare with South Dakota?
55.5 deaths per 100,000 residents a year over 2015–2024, against 14.9 for South Dakota and 11.8 nationally. Rates use Census Bureau population estimates.
What share of fatal crashes in Lyman involved alcohol?
29.4% of fatal crashes in 2015–2024 had at least one driver reported by police as drinking, against 34.9% in South Dakota. The factor furthest above the state share was speeding at 29.4%.
Which roads in Lyman see the most fatal crashes?
Among signed routes with a page on this site, Interstate 90 (6 fatal crashes in the county, 2015–2024).
When do fatal crashes happen in Lyman?
Most often between 6pm to midnight (41% of crashes) and on Thursdays (29%); 29.4% 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.