States › Illinois › Routes › Interstate 255
Interstate 255
Fatal crashes 2015–2024 31Deaths 32Counties 3Latest 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 255 in Illinois, with 32 deaths.
That is 0.3% of the 10,472 fatal crashes in Illinois over the same years. The ten-year crash count rose 72% from 18 in 2005–2014 to 31 in 2015–2024.
The crashes were concentrated in St. Clair County (16), Madison County (11) and Monroe County (4).
19.4% of the crashes had a driver reported as drinking (Illinois: 27.2%) and 32.3% had a speeding-related driver (36.5%); pedestrians were 12.5% and motorcyclists 6.3% 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 Illinois
| Measure | Interstate 255 | Illinois |
|---|---|---|
| Fatal crashes, 2015–2024 | 31 | 10,472 |
| Deaths, 2015–2024 | 32 | 11,423 |
| Deaths per fatal crash | 1.0 | 1.1 |
| Share of state fatal crashes | 0.3% | 100% |
| Change vs previous ten years | +72% | +9% |
Factor shares
Counties along the route
| # | County | Fatal crashes on I-255 | Share of route | County total, all roads |
|---|---|---|---|---|
| 1 | St. Clair County | 16 | 52% | 346 |
| 2 | Madison County | 11 | 35% | 319 |
| 3 | Monroe County | 4 | 13% | 33 |
Hour of day
Share of fatal crashes on Interstate 255 beginning in each hour, 2015–2024; tick marks the Illinois share for all roads.
Where along the route
| Mile marker range | Fatal crashes | Share |
|---|---|---|
| Mile 0–5 | 15 | 48% |
| Mile 5–10 | 5 | 16% |
| Mile 15–20 | 4 | 13% |
| Mile 10–15 | 3 | 10% |
| Mile 20–25 | 2 | 6% |
| Mile 25–30 | 1 | 3% |
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 Illinois
- Interstate 55 255
- Interstate 57 219
- Interstate 94 158
- Interstate 80 127
- US Route 45 122
- State Route 83 116
- State Route 1 106
- Interstate 90 105
- State Route 50 104
- US Route 20 103
- US Route 30 98
- US Route 41 89
All routes and counties in Illinois
Questions and answers
How many fatal crashes have there been on Interstate 255 in Illinois?
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 255 had the most fatal crashes?
St. Clair County (16), Madison County (11) and Monroe County (4).
What share of crashes on Interstate 255 involved alcohol or speeding?
19.4% had a driver reported as drinking and 32.3% a speeding-related driver, against 27.2% and 36.5% for all fatal crashes in Illinois.
When do fatal crashes happen on Interstate 255?
48.4% 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.