Improper Load Distribution

Improper load distribution is one of the least visible causes of truck instability. A load can be strapped down, blocked, braced, and still make the vehicle unsafe if the weight is placed too high, too far back, too far forward, or too far to one side. Federal regulations reflect that distinction. Section 392.9 does not only require cargo to be secured; it states that a driver may not operate, and a motor carrier may not permit operation of, a commercial motor vehicle unless the cargo is “properly distributed and adequately secured.”¹

That wording matters because distribution affects handling even when cargo never falls from the trailer:

These are vehicle-dynamics problems, not merely tie-down problems.

Federal cargo-securement rules still matter because they connect cargo placement to vehicle stability. Section 393.100 requires cargo to be contained, immobilized, or secured to prevent shifting to the extent that the vehicle’s stability or maneuverability is adversely affected. Section 393.102 sets performance criteria for cargo securement systems, including forward, rearward, and lateral force requirements. But those rules do not eliminate the separate problem of a load that was placed in a dangerous configuration before the truck left the dock.²

The practical rule is simple. Cargo must be both secure and balanced. Securement prevents cargo from moving or falling. Distribution determines how the truck behaves when it accelerates, brakes, turns, changes lanes, encounters wind, or travels through a ramp. A load that is tied down but stacked high or placed off-center may still create rollover risk because the truck’s center of gravity and axle loads are wrong before the first mile is driven.

How Weight Placement Changes Truck Handling

The FMCSA Commercial Driver’s License Manual explains the problem in plain terms. It warns drivers not to be top-heavy because the height of the vehicle’s center of gravity is important for safe handling. Cargo piled high or heavy cargo placed on top makes a vehicle more likely to tip over, especially in curves or when the driver must swerve to avoid a hazard. The manual instructs that cargo should be distributed as low as possible, with the heaviest cargo placed under lighter cargo.³

The CDL Manual also warns that poor front-to-back balance can make vehicle handling unsafe:

These are not theoretical concerns. A driver hauling an improperly balanced load may feel the effect as delayed steering response, poor tracking, trailer sway, reduced traction, or instability in curves.⁴

FMCSA’s cargo securement materials give the rollover risk numerical context. FMCSA states that typical lateral acceleration while driving in a curve or on a ramp at the posted advisory speed ranges from 0.05 g to 0.17 g. Loaded vehicles with a high center of gravity may roll over at lateral acceleration above about 0.35 g, while lightly loaded vehicles or heavily loaded vehicles with a lower center of gravity may withstand lateral acceleration above 0.5 g.⁵

NHTSA made the same point when issuing the heavy-vehicle electronic stability control rule. The agency explained that heavy vehicles, particularly loaded vehicles, have a greater propensity to roll during severe crash-avoidance maneuvers or while negotiating curves. NHTSA also noted that tractor-trailer combinations have different center-of-gravity heights and rollover threshold limits between the tractor and trailer, and that combination-vehicle rollovers frequently begin with trailer wheel lift.⁶

That is why improper load distribution can cause a crash even when the cargo does not visibly shift:

• If heavy freight is placed high, the rollover threshold drops.
• If weight is concentrated toward one side, the vehicle may become less stable when turning or when wind pushes from a particular direction.
• If weight is placed too far rearward, the trailer may sway.

The driver may experience the crash as a sudden loss of control, but the mechanical setup for that loss of control may have been created at the loading dock.

Top-Heavy, Rear-Heavy, and Side-Heavy Loads

Top-heavy loading is the most direct rollover problem. A truck’s rollover threshold depends heavily on the relationship between center-of-gravity height and track width. When heavy items are stacked high, the same curve speed or steering input produces a larger overturning moment. FMCSA’s driver guidance tells commercial drivers to be especially cautious with loaded trailers because loaded trailers have a higher center of gravity, and sudden speed adjustment may cause load shift, skidding, or rollover. FMCSA also states that fully loaded trailers are 10 times more likely to roll over than empty trailers.⁷

Rear-heavy loading creates a different problem. When too much trailer weight is placed behind the proper balance point, the tow unit may lose steering authority and the trailer may become more prone to sway. NHTSA’s towing-safety guidance explains that manufacturers account for loaded trailer weight when specifying tongue weight. Too little tongue weight can cause trailer sway, while too much tongue weight can reduce weight on the tow vehicle’s front wheels and make steering less responsive. Although that guidance is written for towing safety generally, the physics apply to many commercial trailer configurations. Front-to-back distribution determines how weight is carried by the hitch, axles, and steering system.⁸

Side-heavy loading can be harder to detect. A trailer may look level at the dock and still carry more weight on one side. NHTSA’s electronic stability control rule recognizes that cargo placed off-center in a trailer may make the vehicle less stable in one direction than the other. That matters in ramp curves, lane changes, evasive maneuvers, cross-sloped roads, and wind. A side-heavy load does not need to break loose to affect the truck’s behavior; it changes the lateral stability margin before the driver turns the wheel.⁹

Wind can amplify those distribution problems. A study on truck rollover propensity under crosswinds found that wind speed and direction influence roll stability, reporting that trucks had a substantially higher chance of rollover in 40 mph winds than in 20 mph winds when other variables were held constant. That source should be used cautiously because it is not a case study of side-heavy cargo. But it supports the broader point that lateral forces from wind interact with vehicle weight, stability, and load condition.¹⁰

The distribution problem is clearest with cargo tanks. Liquid cargo can move inside the tank, changing the center of gravity during a turn or evasive maneuver. FMCSA’s Cargo Tank Roll Stability Study found that cargo-tank rollover risk is closely linked to loading condition and that 94.1 percent of rollovers in MCMIS data, 77.1 percent of cargo-tank rollovers in LTCCS data, and more than 71.3 percent of TIFA cargo-tank rollovers occurred among trucks with at least partial loads.¹¹

Crash Data Shows Why Distribution Matters

Rollover crashes are a recurring large-truck crash mode. FMCSA’s Large Truck and Bus Crash Facts 2022 reports thatoverturn, or rollover, was the first harmful event in 4 percent of fatal crashes involving large trucks and 2 percent of nonfatal crashes involving large trucks. Those numbers do not identify improper distribution as the cause of each rollover, but they establish why load balance matters: rollovers remain a measurable part of the large-truck crash problem.¹²

Research using the Large Truck Crash Causation Study also connects rollover risk to load characteristics. One analysis of large-truck rollover crashes reported that the LTCCS included 239 crashes in which a truck rolled over and identified load-related issues when drivers failed to account for the load’s weight, height, or security, or when the vehicle was loaded before the driver was assigned.¹³

NTSB investigations show how these forces appear in real crash reconstruction. In the Indianapolis cargo tank rollover, NTSB analyzed the relationship between vehicle speed, steering input, cross slope, lateral acceleration, and liquid-load movement. The agency concluded that the rollover dynamics involved not only speed through the curve, but also excessive rapid steering inputs, vehicle instability from a negative cross slope, and side-to-side displacement of the partial bulk liquid load.¹⁴

The Stroud, Alabama propane cargo tank crash illustrates a related loading problem—overloading. NTSB found that the driver had repeatedly loaded propane cargo tanks above specified amounts and reported that he had overloaded his tank on 80 percent of his loads in the month before the crash. That case is not simply a side-to-side distribution case, but it shows why loading tickets, terminal procedures, driver habits, and company oversight matter in cargo-related crash investigations.¹⁵

The 2025 NTSB report on the Philadelphia I-95 crash provides another modern rollover reconstruction example. A gasoline cargo tank combination vehicle entered a left curve on an exit ramp, rolled onto its right side, and released gasoline that fueled a post-crash fire and bridge collapse. The report is not an improper-load-distribution finding, but it shows the kind of evidence investigators examine in rollover cases: ramp geometry, speed, vehicle movement, cargo release, post-crash fire, and physical damage patterns.¹⁶

Litigation Often Turns on Who Loaded the Truck and Who Could See the Problem

Improper load distribution cases are not just engineering cases. They are also responsibility cases. A driver may have the duty to inspect a load before operating, but the driver may not know how cargo was placed inside a sealed trailer, how much each pallet weighed, whether heavy freight was loaded high, or whether the shipper placed dense cargo off-center. Section 392.9 recognizes this practical problem by exempting drivers from certain cargo-inspection duties when the vehicle is sealed and the driver has been ordered not to open it, or when the vehicle has been loaded in a manner that makes inspection impracticable.¹⁷

Texas cases show how courts analyze control over loading. In Texas Specialty Trailers, Inc. v. Jackson & Simmen Drilling Co., the Fort Worth Court of Appeals discussed evidence that a hauler was responsible for loading, securing, blocking, and properly distributing the weight of a drilling rig across a trailer. The case is useful because it shows that loading responsibility may depend on who controlled the loading process, who inspected the load, and who represented that the equipment could be safely moved.¹⁸

Federal courts applying Texas law have also discussed the allocation of duties between carriers, shippers, and others involved in loading. In Sanchez v. Maverick Express Carriers, LLC, the Western District of Texas summarized the widely cited Savage rule, under which the carrier generally has the primary duty for safe loading, but a shipper that undertakes loading may be responsible for latent or concealed defects that ordinary observation would not reveal.¹⁹

That distinction becomes important in improper-distribution litigation. A driver may be able to see that cargo is unsecured. The driver may not be able to determine that the heaviest pallets are stacked high inside shrink-wrapped freight, that a sealed trailer is rear-heavy, or that a cargo tank was improperly filled for the route. The key evidence is often not a single strap or chain.

It is the entire loading process:

Cargo incidents can also create secondary disputes over cleanup, towing, storage, and responsibility after a crash. In Unimex Logistics, LLC v. Tim Neff Towing, Inc., the Beaumont Court of Appeals addressed a dispute arising from towing, recovery, cleanup, and storage services after an eighteen-wheeler cargo incident. The case is not a load-distribution mechanics source, but it illustrates how a cargo-related crash can produce litigation beyond the immediate collision: recovery bills, cleanup invoices, cargo handling, storage, and allocation of responsibility.²⁰

Discovery Must Reconstruct the Load Before the Crash

The most important evidence in an improper-load-distribution case may be created before the truck ever enters the highway.

The following can show how the load was built, who built it, what the driver knew, and whether the truck was weighed or rebalanced before departure:

• Bills of lading, weight tickets, and loading diagrams
• Warehouse records and forklift logs
• Dock video and scale tickets
• Rate confirmations, load tenders, and dispatch instructions
• Text messages
• ELD/GPS data

A trucking litigation guide from Slack Davis identifies bills of lading, weight tickets, toll records, GPS or satellite tracking data, cell phone records, logbooks, trip receipts, driver qualification files, onboard-system data, and video-system data as records to obtain in a commercial truck crash case.²¹

Record retention rules matter because load evidence disappears quickly. Part 379 of the Federal Motor Carrier Safety Regulations applies preservation-of-record rules to motor carriers and brokers. Its schedule includes bills of lading, shipping documents, dispatchers’ sheets, records related to weighing freight, and records of loading and unloading transportation equipment. It also requires records subject to the part to be protected from destruction, deterioration, unauthorized access, modification, and data corruption.²²

Electronic discovery is especially important because modern loading decisions often live in software systems. Warehouse management systems may show pallet sequence and product weights. Transportation management systems may show load tenders, route instructions, trailer assignments, and carrier communications. Telematics may show speed, braking, roll-stability events, location, and stops. In Texas, In re Weekley Homes explains that requests for electronic or magnetic data must specifically request that data and specify the form of production. That principle matters in trucking cases because a generic request for “documents” may not capture native dispatch data, GPS exports, metadata, dock video files, or deleted electronic communications.²³

Spoliation issues often arise when video is overwritten, telematics data expires, a trailer is repaired, cargo is disposed of, or a load file is incomplete. In Brookshire Brothers v. Aldridge, the Texas Supreme Court held that spoliation requires a court to determine whether a party had a duty to preserve evidence and breached that duty, and that any remedy must be proportionate to culpability and prejudice. That framework is relevant when load-distribution evidence disappears before it can be inspected or downloaded.²⁴

A complete investigation should reconstruct the load as it existed at departure, during the trip, and after the crash.

That means identifying:

The question is not simply whether cargo fell. The deeper question is whether the truck was made unstable by the way its weight was arranged.

Improper load distribution is dangerous because it hides inside ordinary freight movement. The load may look secure. The doors may be closed. The straps may be tight. But if the weight is high, rearward, or off-center, the truck can become unstable before anything shifts. In a crash investigation, that makes the loading record as important as the skid marks, the rollover path, and the driver’s speed.

Sources

• [1] Federal Motor Carrier Safety Administration, 49 C.F.R. § 392.9, Inspection of Cargo, Cargo Securement Devices and Systems.
• [2] Federal Motor Carrier Safety Administration, 49 C.F.R. § 393.100, Applicability and General Requirements of Cargo Securement Standards; and 49 C.F.R. § 393.102, Minimum Performance Criteria for Cargo Securement Devices and Systems.
• [3] Federal Motor Carrier Safety Administration, Commercial Driver's License Manual, 2005 CDL Testing System (July 2010).
• [4] Federal Motor Carrier Safety Administration, Commercial Driver's License Manual, 2005 CDL Testing System (July 2010).
• [5] Federal Motor Carrier Safety Administration, Cargo Securement Rules.
• [6] National Highway Traffic Safety Administration, Federal Motor Vehicle Safety Standards; Electronic Stability Control Systems for Heavy Vehicles, Final Rule, 49 C.F.R. Part 571.
• [7] Federal Motor Carrier Safety Administration, CMV Driving Tips – Too Fast for Conditions.
• [8] National Highway Traffic Safety Administration, Towing Safety guidance.
• [9] National Highway Traffic Safety Administration, Federal Motor Vehicle Safety Standards; Electronic Stability Control Systems for Heavy Vehicles, Final Rule, 49 C.F.R. Part 571.
• [10] ScienceDirect, study on truck rollover propensity under crosswinds.
• [11] Federal Motor Carrier Safety Administration, Cargo Tank Roll Stability Study, Final Report (April 30, 2007).
• [12] Federal Motor Carrier Safety Administration, Large Truck and Bus Crash Facts 2022.
• [13] McKnight, A. James, and George T. Bahouth, "Analysis of Large Truck Rollover Crashes," Annals of Advances in Automotive Medicine 52 (2008): 281–288.
• [14] National Transportation Safety Board, Rollover of a Truck-Tractor and Cargo Tank Semitrailer Carrying Liquefied Petroleum Gas and Subsequent Fire, Indianapolis, Indiana, October 22, 2009, NTSB/HAR-11/01 (adopted July 26, 2011).
• [15] National Transportation Safety Board, Commercial Vehicle Overturn Resulting in Cargo Tank Rupture, Propane Release, and Fire, Stroud, Alabama, March 11, 2016, NTSB/HAR-18/01/SUM (adopted January 23, 2018).
• [16] National Transportation Safety Board, Combination Vehicle Rollover, Fire, and Interstate 95 Overpass Collapse, Philadelphia, Pennsylvania, June 11, 2023, NTSB/HIR-25-01 (March 19, 2025).
• [17] Federal Motor Carrier Safety Administration, 49 C.F.R. § 392.9(b)(4), Inspection of Cargo, Cargo Securement Devices and Systems.
• [18] Texas Specialty Trailers, Inc. v. Jackson & Simmen Drilling Co., No. 2-07-228-CV, 2009 WL 2462530 (Tex. App.—Fort Worth Aug. 13, 2009, no pet.)
• [19] Sanchez v. Maverick Express Carriers, LLC, No. EP-21-CV-155, 2021 U.S. Dist. LEXIS 155280 (W.D. Tex. 2021).
• [20] Unimex Logistics, LLC v. Tim Nef Towing, Inc., No. 09-16-00275-CV, 2018 WL 2339623 (Tex. App.—Beaumont May 24, 2018, no pet.)
• [21] Davis, Mike, Handling the Commercial Truck Crash Case, Slack & Davis, LLP (2009, updated 2018).
• [22] Federal Motor Carrier Safety Administration, 49 C.F.R. Part 379, Preservation of Records.
• [23] In re Weekley Homes, L.P., 295 S.W.3d 309 (Tex. 2009).
• [24] Brookshire Bros. v. Aldridge, 438 S.W.3d 9 (Tex. 2014).