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Interstate 405
Fatal crashes 2015–2024 31Deaths 32Counties 2Latest 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. The route is the trafficway recorded for each crash (FARS TWAY_ID); the same route number in another state has its own page.
Between 2015 and 2024, FARS records 31 fatal crashes on Interstate 405 in Washington, with 32 deaths.
That is 0.5% of the 5,793 fatal crashes in Washington over the same years. The ten-year crash count rose 24% from 25 in 2005–2014 to 31 in 2015–2024.
The crashes were concentrated in King County (26) and Snohomish County (5).
35.5% of the crashes had a driver reported as drinking (Washington: 31.1%) and 51.6% had a speeding-related driver (31.1%); pedestrians were 9.4% and motorcyclists 21.9% of those killed.
Fatal crashes per year
Route identification in FARS is consistent from 2000; earlier years are not shown. Shaded band: the ten-year window used for the shares below.
Compared with all fatal crashes in Washington
| Measure | Interstate 405 | Washington |
|---|---|---|
| Fatal crashes, 2015–2024 | 31 | 5,793 |
| Deaths, 2015–2024 | 32 | 6,257 |
| Deaths per fatal crash | 1.0 | 1.1 |
| Share of state fatal crashes | 0.5% | 100% |
| Change vs previous ten years | +24% | +23% |
Factor shares
Counties along the route
| # | County | Fatal crashes on I-405 | Share of route | County total, all roads |
|---|---|---|---|---|
| 1 | King County | 26 | 84% | 1,182 |
| 2 | Snohomish County | 5 | 16% | 443 |
Hour of day
Share of fatal crashes on Interstate 405 beginning in each hour, 2015–2024; tick marks the Washington share for all roads.
Where along the route
| Mile marker range | Fatal crashes | Share |
|---|---|---|
| Mile 0–5 | 12 | 39% |
| Mile 20–25 | 6 | 19% |
| Mile 25–30 | 5 | 16% |
| Mile 15–20 | 3 | 10% |
| Mile 5–10 | 2 | 6% |
| Mile 10–15 | 2 | 6% |
Five-mile bins by FARS milepoint, the six with the most fatal crashes; 96.8% of crashes on the route have a milepoint. Milepoints are as recorded by the state and can restart at county or district lines.
Other routes in Washington
- Interstate 5 390
- Interstate 90 161
- State Route 99 138
- US Route 2 117
- US Route 101 97
- State Route 20 84
- US Route 12 83
- Interstate 82 79
- US Route 97 79
- State Route 7 79
- US Route 395 77
- State Route 14 52
All routes and counties in Washington
Questions and answers
How many fatal crashes have there been on Interstate 405 in Washington?
31 fatal crashes with 32 deaths over 2015–2024, per NHTSA's FARS. The route is the trafficway recorded for the crash; the same numbered route in another state has its own page.
Which counties along Interstate 405 had the most fatal crashes?
King County (26) and Snohomish County (5).
What share of crashes on Interstate 405 involved alcohol or speeding?
35.5% had a driver reported as drinking and 51.6% a speeding-related driver, against 31.1% and 31.1% for all fatal crashes in Washington.
When do fatal crashes happen on Interstate 405?
58.1% of the crashes were between 6pm and 6am. The hour chart on this page shows the full distribution.
Provenance
Source: NHTSA Fatality Analysis Reporting System, annual national CSV files 2000–2024 (accident, vehicle and person tables), public domain. Route pages are built for signed Interstate, US and state routes with at least 20 fatal crashes in 2015–2024. Data through 31 Dec 2024; generated 30 Sep 2026. See methodology and corrections.