Fatal crashes in San Mateo County, California
In 2024, 30 people died in 27 fatal crashes in San Mateo County, California, 21.1% fewer than in 2023. From 2015 to 2024 the county recorded 345 fatal crashes and 369 deaths, the 21st most of 58 counties in California.
4 deaths per 100,000 residents, against 9.8 across California in 2024; 4.9 against 10.1 a year over 2015 to 2024. Population 742,893, Census Bureau estimate. All fatal crashes in California.
Deaths in San Mateo County by year
| Year | Fatal crashes | Deaths |
|---|---|---|
| 2024 | 27 | 30 |
| 2023 | 35 | 38 |
| 2022 | 43 | 48 |
| 2021 | 35 | 36 |
| 2020 | 38 | 39 |
| 2019 | 29 | 30 |
| 2018 | 29 | 30 |
| 2017 | 29 | 33 |
| 2016 | 48 | 52 |
| 2015 | 32 | 33 |
Source: NHTSA Fatality Analysis Reporting System (FARS), 2024 Annual Report File (released April 2026, subject to revision). How we count
The deadliest roads in San Mateo County
US 101 had the most fatal crashes of any numbered road in San Mateo County from 2015 to 2024: 48, with 48 deaths. The 7 roads listed held 61% of all fatal crashes in San Mateo County from 2015 to 2024; 1 is an interstate, 1 US route, 5 state highways. 62% of the county's fatal crashes were on an interstate, US or state route; the other 38% were on county roads and city streets. Routes are listed from 5 fatal crashes.
| Road | Fatal crashes | Deaths | 2022 to 2024 | ||
|---|---|---|---|---|---|
| 1 | US 101 | 48 | 48 | 9 | |
| 2 | State Highway 1 | 43 | 52 | 14 | |
| 3 | I-280 | 32 | 34 | 16 | |
| 4 | State Highway 82 | 31 | 33 | 12 | no page |
| 5 | State Highway 35 | 24 | 28 | 6 | no page |
| 6 | State Highway 84 | 20 | 21 | 3 | no page |
| 7 | State Highway 92 | 11 | 12 | 6 | no page |
Daly City had 9.3% of the county's fatal crashes from 2015 to 2024, 32 of 345.
Cities NHTSA filed, with their fatal crashes from 2015 to 2024: Daly City 32, South San Francisco 29, San Mateo 27, Redwood City 21, Burlingame 14, Menlo Park 12, East Palo Alto 12, San Bruno 11. The city is not filed for crashes outside a city.
Source: NHTSA Fatality Analysis Reporting System (FARS), 2024 Annual Report File (released April 2026, subject to revision). How we count
When fatal crashes happen in San Mateo County
The heaviest slot is Friday, 8 pm to midnight, with 19 fatal crashes from 2015 to 2024. The worst hour is 10 pm to 11 pm; the worst month is April.
| Midnight to 4 | 4 to 8 am | 8 to noon | Noon to 4 | 4 to 8 pm | 8 to midnight | |
|---|---|---|---|---|---|---|
| Sun | 3.3 percent, 11 fatal crashes | 1.5 percent, 5 fatal crashes | 2.1 percent, 7 fatal crashes | 2.4 percent, 8 fatal crashes | 2.4 percent, 8 fatal crashes | 3.3 percent, 11 fatal crashes |
| Mon | 3.0 percent, 10 fatal crashes | 1.5 percent, 5 fatal crashes | 0.3 percent, 1 fatal crash | 2.7 percent, 9 fatal crashes | 2.7 percent, 9 fatal crashes | 1.8 percent, 6 fatal crashes |
| Tue | 1.8 percent, 6 fatal crashes | 1.8 percent, 6 fatal crashes | 1.5 percent, 5 fatal crashes | 3.0 percent, 10 fatal crashes | 2.1 percent, 7 fatal crashes | 1.8 percent, 6 fatal crashes |
| Wed | 1.8 percent, 6 fatal crashes | 2.4 percent, 8 fatal crashes | 1.2 percent, 4 fatal crashes | 2.1 percent, 7 fatal crashes | 1.5 percent, 5 fatal crashes | 1.2 percent, 4 fatal crashes |
| Thu | 1.2 percent, 4 fatal crashes | 2.7 percent, 9 fatal crashes | 0.9 percent, 3 fatal crashes | 2.1 percent, 7 fatal crashes | 2.4 percent, 8 fatal crashes | 3.9 percent, 13 fatal crashes |
| Fri | 0.9 percent, 3 fatal crashes | 1.5 percent, 5 fatal crashes | 1.8 percent, 6 fatal crashes | 2.1 percent, 7 fatal crashes | 4.8 percent, 16 fatal crashes | 5.7 percent, 19 fatal crashes |
| Sat | 3.0 percent, 10 fatal crashes | 2.1 percent, 7 fatal crashes | 2.1 percent, 7 fatal crashes | 4.2 percent, 14 fatal crashes | 5.1 percent, 17 fatal crashes | 4.2 percent, 14 fatal crashes |
By hour
By month
- Jan9.3%
- Feb9.0%
- Mar7.0%
- Apr11.3%
- May8.1%
- Jun8.4%
- Jul9.3%
- Aug7.0%
- Sep9.3%
- Oct5.8%
- Nov7.8%
- Dec7.8%
Source: NHTSA Fatality Analysis Reporting System (FARS), 2024 Annual Report File (released April 2026, subject to revision). How we count
What fatal crashes in San Mateo County first hit
The first harmful event was a pedestrian in 29%; a fixed object such as a tree, pole or barrier in 27%, a collision with another vehicle in 26%, a rollover in 5.8%.
| First harmful event | Fatal crashes | Share |
|---|---|---|
| Pedestrian | 101 | 29% |
| Fixed object (tree, pole, barrier, ditch) | 92 | 27% |
| Collision with another vehicle | 90 | 26% |
| Rollover | 20 | 5.8% |
| Cyclist | 18 | 5.2% |
| Other | 14 | 4.1% |
| Parked vehicle | 10 | 2.9% |
| Not reported | 0 | 0.0% |
Source: NHTSA Fatality Analysis Reporting System (FARS), 2024 Annual Report File (released April 2026, subject to revision). How we count
How fatal crashes in San Mateo County compare with California
The largest difference from California: from 2015 to 2024, 19% of fatal crashes in San Mateo County were on rural roads, against 30% across California. Below the California share: drinking drivers and unbelted occupants. Shares of fatal crashes from 2015 to 2024, against the share across all of California. A share is only given over 20 crashes; above or below means more than chance would give on 345 crashes.
| San Mateo | California | ||
|---|---|---|---|
| On rural roads | 19% | 30% | below the California share |
| At or near an intersection | 23% | 27% | about the same as the California share |
| In the dark, road unlit | 22% | 25% | about the same as the California share |
| A drinking driver | 21% | 28% | below the California share |
| Speeding | 33% | 30% | about the same as the California share |
| A distracted driver (as recorded) | 4.3% | 4.1% | about the same as the California share |
| Occupants killed unbelted | 28% | 38% | below the California share |
| Hit-and-run | 12% | 11% | about the same as the California share |
| A motorcycle involved | 15% | 15% | about the same as the California share |
| Pedestrians among the dead | 30% | 26% | about the same as the California share |
Source: NHTSA Fatality Analysis Reporting System (FARS), 2024 Annual Report File (released April 2026, subject to revision). How we count
Questions about fatal crashes in San Mateo County, California
- How many people died in car accidents in San Mateo County in 2024?
- 30 people died in 27 fatal crashes in San Mateo County, California, in 2024, 21.1% fewer than in 2023. That is 4 deaths per 100,000 residents, against 9.8 across California. Source: NHTSA's Fatality Analysis Reporting System (FARS).
- What is the deadliest road in San Mateo County?
- US 101 had the most fatal crashes of any numbered road in San Mateo County from 2015 to 2024: 48, with 48 deaths.
- When do fatal crashes in San Mateo County happen most often?
- The heaviest slot from 2015 to 2024 was Friday, 8 pm to midnight, with 19 fatal crashes.
- How many fatal crashes in San Mateo County involved a drinking driver?
- 72 of 345 fatal crashes in San Mateo County from 2015 to 2024 involved a driver NHTSA recorded as drinking, 21%, against 28% across California.
Other counties in California with a page
- Los Angeles County
- San Bernardino County
- Riverside County
- San Diego County
- Orange County
- Sacramento County
- Kern County
- Fresno County
- Santa Clara County
- San Joaquin County
- Alameda County
- Contra Costa County
All fatal crashes in California, with every county ranked.
Where the San Mateo County numbers come from
Counted from NHTSA's Fatality Analysis Reporting System, 2024 Annual Report File: every fatal crash NHTSA filed in San Mateo County (county code 81). A fatal crash is one in which someone died within 30 days. The rate per 100,000 uses the Census Bureau's population estimate for the county; it is the only figure here not counted from FARS. Totals from state highway departments and news reports can differ: they count from their own crash reports, often before every death within 30 days is known, while NHTSA's file is checked against death certificates and revised once a year. The full method.
Download every county with a page as CSV. Free to reuse with credit: “Fatal Crash Data, fatalcrashdata.com/fatal-crashes/california/san-mateo-county/, from NHTSA FARS (2024 Annual Report File).”