The T-bone intersection crash between a motorcycle and a commercial vehicle is one of the highest-mortality configurations in transportation litigation. When a truck crosses an intersection and cuts across the motorcycle's lane of travel, the collision is often catastrophic for the rider regardless of protective equipment. These cases require a specific investigative approach that differs meaningfully from rear-end or lane-change motorcycle cases, and the evidence window is shorter than in most PI matters.
The Liability Theory: What the Truck Operator Was Required to Do
Every commercial vehicle operator entering an intersection has an affirmative duty to scan all lanes of conflicting traffic before proceeding. That duty is codified in FMCSA general driving rules (49 C.F.R. § 392.2, incorporating applicable state traffic laws) and in the commercial driver's license skills test standards that every CDL holder passed before receiving a license. The CDL examination specifically tests whether a driver executes a proper pre-intersection scan covering mirrors, adjacent lanes, and the far edge of the intersection before proceeding through on a green or after stopping at a stop sign.
The duty does not diminish because the crossing vehicle is a motorcycle. Federal motor carrier regulations and every state vehicle code impose an equal duty to yield to all lawfully proceeding traffic regardless of vehicle size. In practice, however, the defendant's accident reconstruction expert will argue that the truck operator simply did not see the motorcycle in time to avoid the collision, which is where the conspicuity and sight-line analysis becomes the centerpiece of the liability case.
Conspicuity and the Defense's Favorite Argument
In intersection-angle motorcycle crashes, defense counsel almost always raises a conspicuity defense: the motorcycle was traveling at a speed or in a position that made it difficult to perceive before the truck entered the intersection. The argument has two components. The first is that small vehicles are harder to detect than larger ones at peripheral angles of approach. The second is that the rider's speed placed the motorcycle in the truck operator's sight path only briefly before impact.
Plaintiff counsel counters on both fronts. The plaintiff's accident reconstruction expert should address the truck operator's sight distance at the intersection geometry: how far the rider was visible from the operator's viewing position, for how many seconds before impact, and at what point the truck committed to its path versus when it could still have yielded. Standard accident reconstruction software can model the truck's approach vector, the motorcycle's approach vector, and the perception-reaction time available to the truck driver with input from intersection geometry, speed calculations from post-impact evidence, and traffic signal timing data.
Traffic signal controller data is frequently overlooked. Every modern signalized intersection stores event logs in its controller cabinet, including phase activations, detector actuations, and timing intervals. Obtaining those logs through a preservation demand and public records request early in the case can establish precisely how long the truck had a yellow or red signal before it cleared the intersection, and whether the motorcycle had a clear green or protected phase at the time of impact.
Investigation Steps in the First 48 Hours
- Preserve the carrier's ELD and pre-trip inspection records. Hours-of-service violations and a fatigued driver who skipped the pre-trip tire and brake inspection are separate liability theories. Send a preservation letter by certified mail to both the carrier and the driver within 24 hours of retention.
- Request traffic signal controller data from the city or county signal operations department before it is overwritten. Many jurisdictions purge controller event logs on cycles as short as 30 days.
- Hire a photogrammetrist to reconstruct the sight triangle from the truck operator's eye position. The camera on a cell phone is not sufficient; a professional site inspection with a calibrated fisheye lens matched to the operator's actual seated eye height generates the evidentiary-quality sight-distance calculations that survive a Daubert challenge.
- Preserve the motorcycle. A motorcycle's final resting position, damage pattern, and retained speed-sensitive components (ABS module, instrument cluster, ECU) all provide speed and pre-impact data. The motorcycle must not be moved or repaired before your expert inspects it.
- Identify all cameras. Traffic cameras are obvious targets; less obvious are business security cameras, ATM cameras, and cameras mounted on other vehicles in the vicinity. A canvass of businesses on all four corners of the intersection often uncovers footage the police did not pull.
Commercial Vehicle Defendant-Identification Checklist
In commercial truck intersection crashes, liability may extend beyond the driver and the motor carrier. The shipper, who loaded the vehicle and may have caused a delayed departure that created schedule pressure on the driver, may be relevant where fatigue is part of the theory. The broker, if applicable, should be evaluated under the standard established by recent decisions on carrier selection negligence. The truck's lessor may also have separate liability where a mechanical defect, such as brake pull or steering play, contributed to the inability to yield.
For resources on commercial trucking discovery and carrier identification, see truck and motorcycle litigation practice. Where intersection design contributed to the crash, the government-entity roadway defect framework covered in auto-accident litigation resources applies to the public-entity defendant.