Truck accident claims in Ontario, California

1,348 of the 8,200 crashes officers reported in Ontario across 2023, 2024 and 2025 involved a commercial truck, and 888 of those involved a tractor-trailer combination rather than a straight truck.

Why the tractor-trailer split is the useful number

A straight truck is usually one company's vehicle with one company's driver. A tractor-trailer often is not: the tractor, the trailer and the load can belong to three different businesses, and the driver may be employed by a fourth or by none of them. Every one of those relationships is a place responsibility can sit, and sorting out which is which is most of the early work in a truck case. Who is liable in a truck case.

In Ontario that split was 888 tractor-trailer crashes against 460 involving other commercial trucks — box trucks, tankers, tow trucks and the like. The difference between a semi and a box truck · delivery and box trucks.

Where trucks are in Ontario

The state-route and freeway segments named most often on Ontario reports were I-10 E/B (San Bernardino Fwy) (1,170), I-10 W/B (San Bernardino Fwy) (751), I-15 S/B (Ontario Fwy) (502) and SR-60 E/B (Pomona Fwy) (486). 54% of all Ontario crashes carried the freeway flag. Freight follows the freeway, so a truck case here is more likely than a car case to be a CHP investigation on a state route — which changes who holds the report and how quickly it can be obtained.

What has to happen quickly

Commercial carriers run on federal safety rules — driver qualification files, hours-of-service records, inspection and maintenance records — and every one of those is a document with a retention schedule. Engine control module data can overwrite itself in a matter of days of continued driving. The single most useful thing after a truck crash is a preservation letter reaching the carrier before the ordinary cycle destroys the evidence.

Black box and ECM data · hours of service · FMCSA violations · why these cases move fast.

A question about Ontario

Which Ontario roads carry the most reported crashes?

The freeway segments are I-10 E/B (San Bernardino Fwy), I-10 W/B (San Bernardino Fwy), I-15 S/B (Ontario Fwy). On surface streets it is Euclid Av, Holt Bl, Fourth St. That is the road named first on the report, across all crashes rather than truck crashes alone, so read it as where traffic concentrates in Ontario and not as a freight route. Which road a crash happened on can matter later: a state highway, a city street and a county road are maintained by different public bodies, and a claim against a public body has its own short deadline.

The general questions — how fault is decided, what happens when the other driver has no insurance, whether being partly at fault ends a claim — are answered once on the truck accidents page rather than repeated on every city page.

Sources: counts from the California Crash Reporting System (CCRS), California Highway Patrol, 2023, 2024 and 2025 exports, retrieved 2026-09-06. Counts are of reported crashes and are not adjusted for exposure; method and limitations.

This is general information, not legal advice.