A truck stopped in a lane is the most dangerous thing on the road that is not moving, and federal law gives its driver ten minutes to say so. Warning devices is the regulation’s phrase for the three triangles carried in every cab, and the clock on them starts the moment the truck stops.
The rule has two parts and a timer. “Whenever a commercial motor vehicle is stopped upon the traveled portion of a highway or the shoulder of a highway for any cause other than necessary traffic stops, the driver of the stopped commercial motor vehicle shall immediately activate the vehicular hazard warning signal flashers.” Then, “as soon as possible, but in any event within 10 minutes,” the driver must place the warning devices: “One on the traffic side of and 4 paces (approximately 3 meters or 10 feet) from the stopped commercial motor vehicle in the direction of approaching traffic,” one “at 40 paces (approximately 30 meters or 100 feet)” behind it in the center of the lane or shoulder it occupies, and one a hundred feet ahead. On a divided or one-way highway the pattern shifts to the traffic that matters: “one warning device at a distance of 200 feet and one warning device at a distance of 100 feet in a direction toward approaching traffic,” and one “within 10 feet of the rear.” Within 500 feet of a curve or the crest of a hill, the far device goes back past the obstruction, “a distance of 100 feet to 500 feet from the stopped commercial motor vehicle so as to afford ample warning to other users of the highway.” Inside a business or residential district the triangles are not required unless lamps are, and the street lighting cannot show the truck at 500 feet (49 CFR 392.22). The devices themselves are either “Three bidirectional emergency reflective triangles” built to the federal standard or at least six fusees, the flares, and a truck carrying explosives, a tank truck carrying flammable gas or flammable liquid, or a truck that runs on compressed gas may not carry a flame at all (49 CFR 393.95).
The manual says why in two sentences every driver was tested on. “Don’t trust the taillights to give warning.” “Drivers have crashed into the rear of a parked vehicle because they thought it was moving normally.” It repeats the ten minutes, the ten, one hundred and two hundred feet, the rule for hills and curves, and one instruction for the driver’s own life: “When putting out the triangles, hold them between yourself and the oncoming traffic for your own safety” (CDL manual, Section 2.5.2). The reason a parked truck looks like a moving one is the subject of Looking, Not Seeing: a stopped object produces almost none of the swelling on the retina the brain uses to feel a closing distance, so a driver can look straight at a trailer and not know it is standing still until the road is gone. The triangle is the thing on the road that is unmistakably not traffic. And the distances are smaller than they sound. At seventy miles an hour a car covers about 103 feet every second, so the two-hundred-foot triangle on a divided highway is two seconds out, and the hundred-foot one is one. That is the margin the rule buys, and it is why the rule says ten feet, a hundred and two hundred rather than one triangle at the bumper.
Texas law decides whether the truck may be there at all. Outside a business or residence district, an operator “may not stop, park, or leave standing an attended or unattended vehicle on the main traveled part of a highway” unless stopping off it “is not practicable,” the road beside it is open and the vehicle is in clear view for 200 feet each way; but the rule “does not apply to an operator of” “a vehicle that is disabled while on the paved or main traveled part of a highway if it is impossible to avoid stopping and temporarily leaving the vehicle on the highway” (Transportation Code Section 545.301). A broken truck is allowed to be where it broke. What it is not allowed to be is silent about it, because Texas adopts the federal rules as its own for the carriers it regulates (37 Tex. Admin. Code Section 4.11), and the federal rule is the one with the timer.
The move: when a truck runs into a truck that was stopped in a lane, the first instinct is to blame the one that was moving, and Texas asks for “a speed greater than is reasonable and prudent under the circumstances then existing” from no one (Transportation Code Section 545.351; Reasonable and Prudent). But a jury in Texas divides a wreck among everyone who had a hand in it, in whole-number percentages (Civil Practice and Remedies Code Section 33.003), which is Comparative Fault, and the stopped truck’s share is written in the ten minutes. When did it stop, which its engine recorder and its driver’s phone both know. When did the flashers go on. Were the triangles out, and where, which the responding officers’ photographs show and the triangles themselves prove, found on the road or still in their case behind the seat. How long between the stop and the crash, because a truck hit nine minutes after it stopped had a driver who was still inside the rule, and one hit forty minutes later did not. A missing triangle is a safety regulation broken, which is where Negligence Per Se begins, and the driver who hit it will reach for Sudden Emergency, which the instruction allows only for an emergency he did not help create. One caution. The triangle does not excuse the driver who did not look, and the lack of one does not convict the truck that had nine minutes left. The rule sets the clock; the record says where each driver was on it. Spoliation is the letter that asks for the record, and the triangles, before either one is swept up.
49 CFR 392.22 (paragraphs (a), (b)(1), (b)(1)(i) through (iii), (b)(2)(iii), (b)(2)(iv) and (b)(2)(v)); 49 CFR 393.95 (paragraphs (f)(1), (f)(2) and (g)). Commercial driver’s manual, Section 2.5, Communicating, as posted by the Georgia Department of Driver Services (2.5.2, Communicating Your Presence, under the heading When Parked at the Side of the Road). Tex. Transp. Code § 545.301 (subsections (a) and (b)(1)); § 545.351 (subsection (a)); 37 Tex. Admin. Code § 4.11 (subsection (a)); Tex. Civ. Prac. & Rem. Code § 33.003 (subsection (a)). The seconds are arithmetic: 70 miles an hour is 5,280 times 70 divided by 3,600, about 102.7 feet a second, so 200 feet is about 1.9 seconds and 100 feet about one second. This is general information, not legal advice. Figures and text as published at publication.
