By Jonathan Herrera, J.D., Herrera PLLC | Houston, Texas
Picture a loaded tanker moving along a freeway ramp near Houston on a clear, dry afternoon. Nothing about the scene suggests danger, and traffic is flowing normally. Then the cab drifts toward the shoulder, the driver steers back sharply, and the trailer begins to lean. Within seconds, tons of steel and cargo can be on their side across several lanes. Many people assume rollovers happen in storms, at night, or on twisting mountain roads. The federal data on one category of rollover points somewhere less expected.
The short answer: truck rollovers usually involve a vehicle with a high center of gravity or a load that can shift, combined with a driver-related event such as drifting, inattention, or a sharp correction. FMCSA’s data on cargo tank trucks suggests weather and road shape are a smaller part of the picture than most people assume. Having spent over a decade as an insurance adjuster handling casualty and property claims from the carrier side, I have seen how often the cause of a rollover turns out to be a chain of events rather than a single moment.
High Center of Gravity and Tanker Loads
A truck’s center of gravity is the point around which its weight is balanced, and the higher that point sits, the less sideways force it takes to tip the vehicle. Large trucks are tall, heavy, and relatively narrow compared with their height, which makes them more vulnerable to tipping than passenger cars. How a truck is loaded can raise or lower that point. Freight stacked high, loads that are unevenly distributed, and cargo that shifts in transit can all move the center of gravity in ways that make a rollover more likely. Federal cargo securement requirements appear in 49 CFR Part 393, and investigators often ask whether a load was properly distributed and secured.
Tanker trucks present a special version of this problem. A tanker has a high center of gravity, and liquid cargo does not stay put. When a tank is only partly full, the liquid can slosh and surge during braking, turning, and steering, shifting weight at the worst possible moment. The Federal Motor Carrier Safety Administration (FMCSA) addresses this in its cargo tank rollover fact sheet, which draws on a 2007 Cargo Tank Roll Stability Study. According to that sheet, about 63 percent of rollover crashes involved cargo tanks carrying partial loads, and the agency says over 1,300 cargo tank rollovers are reported each year.
These loads can carry real hazards. FMCSA notes that the hazardous materials moved by truck each day include crude oil, gasoline, and flammable gases, and that a rollover can cause injury, death, and property damage. In a region like Houston, with its concentration of petrochemical facilities and heavy industrial traffic, tanker traffic is a regular part of the highway mix.
The risk is not limited to tankers. Smaller box trucks and vans used for local delivery can also be affected by load placement, and our delivery and last-mile vehicle accident page discusses how those vehicles raise their own liability questions.
Speed and Curves
Physics explains why speed and curves matter. When a truck turns, sideways force acts on it, and that force increases quickly as speed rises. A loaded truck with a high center of gravity has a lower threshold for tipping, so entering a curve or ramp too fast can push it past that threshold. Texas law reflects the general principle in Section 545.351 of the Texas Transportation Code, which says a driver may not drive faster than is reasonable and prudent under the circumstances. For trucks, what is reasonable can depend on the load, the road, and the vehicle’s condition.
At the same time, FMCSA’s cargo tank data challenges some common assumptions. According to the fact sheet, less than 4 percent of single-vehicle cargo tank rollovers were caused by roadway and environment-related reasons. It also reports that 56 percent of these rollovers happened on straight roads rather than on curves or ramps, roughly two-thirds occurred in daylight, and 93 percent occurred on dry roads. The sheet adds that excessive speed was a contributing factor in less than half of all rollovers, and that 28 percent of cargo tank accidents involved driving too fast for conditions. These figures apply to cargo tanks specifically and rely on a study from 2007, so they should not be read as a statement about every type of truck or about current conditions.
Even so, they illustrate a useful point. Curves and speed are real risk factors, but they are only part of the picture, and a rollover on a straight, dry road in daylight is entirely possible. In a legal claim, speed can be one of several factors examined, along with load condition, vehicle maintenance, and driver attention. The framework of federal trucking regulations that can matter in a Houston accident claim helps explain which of those areas may come into play.
Sudden Steering Corrections and Overcorrection
Where speed and road conditions explain less than many people expect, FMCSA points to driver error. The fact sheet reports that about 78 percent of cargo tank rollovers involved some kind of driver error, and that over 90 percent of the time the rollover was not the first event in the sequence. In other words, something else happened first. The sheet identifies drowsiness and inattention as together contributing to roughly 1 in 5 cargo tank rollovers, and gives examples such as drifting onto a soft shoulder, riding up over a curb, or making a turn incorrectly at an intersection.
That sequence helps explain overcorrection. When a truck’s wheels leave the pavement or a driver realizes the vehicle has drifted, a sharp steering input to return to the lane can transfer weight suddenly to one side. In a truck with a high center of gravity, or with liquid moving inside a partly filled tank, that transfer can be enough to tip the vehicle. FMCSA reports that evasive maneuvers were a factor in only a small percentage, about 5 to 10 percent, of rollovers, so the sheet does not suggest swerving is the leading cause. Still, the first event in a sequence can take many forms, including a vehicle cutting in front of a truck, a topic that overlaps with our discussion of blind spots and No-Zone accidents.
Several lines of inquiry can follow from an initial lapse:
- Fatigue and hours of service. Federal rules in 49 CFR Part 395 address driver hours, and records can show whether a driver was within those limits.
- Distraction. Phone use or other distractions may explain drifting, and our article on distracted driving in commercial trucks covers that issue.
- Impairment. Texas law on truck driver DUI is discussed separately.
- Vehicle condition. FMCSA’s sheet notes that in one study, 54 percent of vehicles in rollovers had a brake defect of some sort. Maintenance and inspection duties are addressed in 49 CFR Part 396.
Why Rollovers Often Involve Multiple Vehicles
A truck that rolls does not stay in one place. A trailer can sweep across several lanes as it falls, strike adjacent vehicles, or block the roadway so that following traffic cannot stop in time. Cargo can spill, fuel can leak, and a single event can quickly involve many people. A truck that crosses a median or drifts into oncoming lanes before rolling may also produce the kind of collision described in our article on Texas head-on collisions and highway liability. Busy Houston corridors such as I-10, I-45, and Highway 288 can compound this, since a rollover in dense traffic may reach a large number of vehicles in a short span. Our South Houston truck accident lawyer page addresses crashes in that part of Harris County.
When several vehicles and companies are involved, responsibility can be complicated. Depending on the facts, claims may look at the driver, the trucking company, a party responsible for loading or securing cargo, and a party responsible for maintenance. Texas follows a proportionate responsibility system under Section 33.001 of the Civil Practice and Remedies Code: a claimant whose percentage of responsibility is greater than 50 percent may not recover damages, and recovery is otherwise reduced by the claimant’s percentage. Having evaluated high-exposure claims from the carrier side, I know insurers study these allocation questions closely, and our overview of what happens inside a truck accident claim explains how that process generally unfolds.
Texas generally allows two years from the date of injury to file a personal injury lawsuit, and two years from the date of death in wrongful death cases, under Civil Practice and Remedies Code Section 16.003. Texas law may allow recovery of categories of damages such as medical expenses, lost wages, and pain and suffering, depending on the facts, and our article on truck accident settlements and compensation in Texas discusses those categories in general terms. For the immediate aftermath of a collision, what to do after a trucking accident in Houston offers background. The firm’s Houston truck rollover accident attorney page describes how these cases are handled, and it sits within the broader truck accidents practice area.
Frequently Asked Questions
What types of trucks are most prone to rolling over?
Any truck can roll over, but vehicles with a higher center of gravity and loads that can move are generally at greater risk. FMCSA’s rollover materials focus on cargo tank trucks, which carry liquids in tall tanks, and the agency reports over 1,300 cargo tank rollovers each year. Other trucks carrying tall, heavy, or poorly secured loads may also be affected. No single vehicle type is the only one at risk, and each crash depends on its own facts.
How does cargo type affect rollover risk?
Cargo affects both how high a truck’s weight sits and how that weight behaves. Tall or unevenly loaded freight can raise the center of gravity, and cargo that shifts can change the balance mid-turn. Liquids add the “slosh and surge” effect, particularly in partly filled tanks. FMCSA’s fact sheet reports that about 63 percent of cargo tank rollover crashes involved partial loads. Hazardous cargo can also raise the stakes if a rollover occurs.
Can speed alone cause a truck to roll over?
Speed can contribute, especially for a loaded truck entering a curve or ramp, but FMCSA’s data suggests it is not the whole story. The agency’s fact sheet says excessive speed was a contributing factor in less than half of cargo tank rollovers, and that 56 percent happened on straight roads. Driver error, inattention, vehicle condition, and loading also appeared in the data. Each crash is evaluated on its own facts.
Are rollover accidents more dangerous than other truck accidents?
Rollovers can be very serious, because a large vehicle on its side may strike other vehicles, block lanes, and release cargo or fuel. FMCSA notes that hazardous materials have the potential to cause injury, death, and property damage when trucks roll over. Whether a rollover is more dangerous than another type of crash depends on the vehicles, the cargo, the location, and the circumstances, and no single ranking applies to every case.
What should I do if I witness a truck rollover accident?
General safety guidance for witnesses commonly includes calling 911 right away, staying at a safe distance because of possible fuel leaks, fire, or hazardous cargo, and avoiding contact with spilled materials. Witnesses are often asked to share what they saw with responding officers, and details such as the location, the direction of travel, and the vehicles involved can be useful. Rescue and emergency personnel should direct any approach to the scene.
This article is for general educational purposes only and is not legal advice or a substitute for advice about your specific situation, and no outcome can be guaranteed. The attorney-client relationship begins only when both sides agree to it.
If you or a family member were hurt in a collision involving a commercial truck, you may have options. You are welcome to contact Herrera PLLC or call 832-891-3210 for a free, confidential consultation with no obligation. Serious injury cases are handled on a contingency fee basis, which means no attorney’s fees are owed unless compensation is recovered, and the firm advances case costs, which are reimbursed only if the case is successful.
Jonathan Herrera, J.D. is the founder of Herrera PLLC in Houston, Texas.
Before becoming an attorney, Jonathan spent over a decade as a licensed insurance adjuster, managing high-exposure casualty and property claims for insurance carriers and third-party administrators across multiple states, and he founded JH Claims LLC, an independent adjusting firm. He later practiced insurance defense at Rymer, Echols, and Nelson-Archer before opening his own firm to represent injury victims, policyholders, and businesses. He is a member of the Texas Trial Lawyers Association, the Houston Trial Lawyers Association, and the American Association for Justice. Learn more about Jonathan Herrera and Herrera PLLC.
