A passenger car that slides under the back of a trailer faces a different kind of danger than one that hits a bumper. Federal rules address that risk with a required piece of hardware on large trailers. Whether that hardware was in place, and in what condition, can shape what happened in a crash.
Federal Rules Require a Rear Guard on Most Trailers
According to 49 CFR 393.86, trailers and semitrailers manufactured on or after January 26, 1998, with a gross vehicle weight rating of 10,000 pounds or more must have a rear-impact guard. The guard has to meet the federal standard known as FMVSS 223. The rule exists to stop a car from sliding under the trailer.
The Guard Has to Sit Low and Wide
The regulation sets dimensions, and they aren’t suggestions. The guard’s bottom edge can’t be more than 22 inches above the ground, and its outermost surfaces must reach within 4 inches of the trailer’s side extremities. It also has to sit within 12 inches of the rear extremity, with a horizontal member at least 100 millimeters tall.
In plain terms, the guard must hang low enough to catch a car’s front end and wide enough to span the rear of the trailer. The numbers matter because a guard that is bent, missing, or mounted too high may not do that job.
Some Trailers Are Exempt
The rule has exceptions. They include certain vehicles such as:
- Pole trailers and pulpwood trailers
- Low-chassis and special-purpose vehicles
- Wheels-back vehicles
- Road construction controlled horizontal discharge trailers
- Driveaway-towaway operations
When a trailer falls into one of those groups, the analysis shifts to whether the exemption really applied. A trucking company may claim an exception that the actual equipment doesn’t support.
Why Guard Condition Matters After a Crash
Trailers can be repaired, sold, or returned to service before anyone measures the guard, so a St. Paul semi truck accident lawyer will want the trailer inspected and measured against the regulation before anything changes.
Photographs should show the bar from the rear and from each side, along with any damage to its mounting. Add the trailer’s identification number, and an engineer has something to work from. Preserving evidence early lets the guard be compared with each dimension in the rule.
Who May Be Responsible
Several parties can bear responsibility for a faulty or missing guard. The trailer’s owner, the company handling its maintenance, and the manufacturer can each come into the picture. Each may point to another, so the paperwork on ownership, service, and repairs matters.
Neglected upkeep is one possibility, and a trail of truck maintenance failures can show that a bent bar went unrepaired. Repair invoices and inspection reports are where that evidence sits.
If the equipment itself was defective, manufacturer liability becomes a separate question. The answer depends on how the guard was built and installed.
What We Do With This Information
At Johnston | Martineau PLLP, we focus on truck accident litigation, including semi-truck, tractor-trailer, and commercial truck crashes. Our attorneys are admitted in Minnesota, and Christopher A. Johnston also holds admissions in Iowa and before the Eighth Circuit. We review equipment records alongside driver records, because a guard problem is one piece of a larger record.
Equipment questions also depend on where a trailer is based and who services it. For a wreck in St. Paul, a St. Paul truck accident lawyer can look into both.
The same questions come up in neighboring Minneapolis. Anyone hurt there can turn to a Minneapolis semi truck accident lawyer who works through the same equipment records.
Questions Worth Asking
If a loved one was hurt in a crash with a trailer, ask where the trailer is now, who owns it, and whether anyone has photographed the rear of it. Those three answers tell an investigator where to start. You can get in touch with us if you’d like help sorting out which inspections matter, and a St. Paul semi truck accident lawyer can explain how the equipment questions fit into the larger claim.
