When a truck loses its grip on the road, the trailer does not stop with the cab. It keeps its own momentum, and the rig folds at the coupling like a closing pocketknife until the trailer lies across lanes it was never in. People call it jackknifing, and they tend to blame the weather. The better question is whether the machine was kept up, because the part that fails inspection most often is the one built to stop the load: the brakes.
The count. In this year’s International Roadcheck, a three-day inspection blitz across North America, inspectors conducted 54,575 inspections and ordered 10,350 commercial vehicles, 19 percent, off the road on the spot. Brake systems were the most common vehicle out-of-service violation, 24.3 percent of them; counting every brake-related violation, the share was 39.1 percent. It holds from year to year. In the 2025 Brake Safety Week, 2,296 of the 15,175 vehicles inspected were placed out of service for their brakes, and the inspectors’ alliance says brake-related violations “continue to be the most cited out-of-service vehicle violation during roadside inspections.”
What the pattern says. A jackknife is a loss of control before it is a crash. When the tractor’s rear wheels lock or lose traction, on wet pavement, in a curve, under hard braking, the loaded trailer keeps pushing and the rig pivots at the coupling; lock the trailer’s wheels instead and the trailer swings out on its own. What makes it a highway catastrophe and not one truck’s problem is geometry. A folding tractor and trailer does not stay in its lane. It sweeps a wall of steel across the road. A car that runs into that wall meets it at its own full speed, or, if the rig has crossed into oncoming lanes, at the sum of both speeds; Closing Speed explains that arithmetic, and Delta-V the change in speed the people inside have to absorb. A loaded trailer stopped across the lanes is, to a car, nearly the unyielding wall The Fixed Object describes, and it rides high enough that a car can slide beneath it, which is Underride. San Antonio saw one this month: a jackknifed 18-wheeler closed the exit from Interstate 35 to Loop 1604, on the city’s Southwest Side, for nearly two hours.
What the law does with it. Texas requires a truck and its trailer to be equipped with brakes that meet the state’s standards (Transportation Code Chapter 547), and federal law puts the deeper duty on the company, not only the driver. Every motor carrier must “systematically inspect, repair, and maintain ... all motor vehicles ... subject to its control” (49 CFR 396.3). That is what Inspection is about: an inspection is a decision, not a document. The driver checks the rig before it rolls, but the brakes, their adjustment, and the maintenance schedule are the carrier’s to keep, and a skipped brake adjustment is one way a rig ends up folded across a highway. The proof is not anyone’s memory of the road. It is the maintenance file, the inspection reports, and the logs the company must keep, and Logbook explains why the record is the first thing to preserve: it is the first thing that disappears. A driver’s mistake on the job is the company’s to answer for (Respondeat Superior), and the company’s own files show whether it put a driver it knew or should have known was unfit behind the wheel (Negligent Entrustment). One honest caution: a jackknife by itself is not a verdict. Pavement and speed are in the mix, and Texas divides the fault among everyone who played a part (Comparative Fault). The trucking company liability page names skipped maintenance among a carrier’s own failures, and the truck accidents Before You Call explains why the preservation letter goes out before the company’s records can be overwritten.
No one is named here, and nothing on this page decides a particular crash. A dispatch keeps the record of what the numbers say about the trucks on the road, next to the pages that explain why, when a rig folds across a highway, the first place to look is the truck’s maintenance file.
Dispatch is the Night Docket’s news strand: what happened on Texas roads and in Texas courts, reported from credible outlets and agency releases, with no names and no conclusions about open investigations, then connected to the entries that explain the science and the law. General information, not legal advice.
