Cargo on the CDL General Knowledge Test: Weight, Tie-Downs, and When to Recheck

The cargo knowledge area and the driver's responsibility

Cargo is General Knowledge area 16 in federal rules, titled "relationship of cargo to vehicle control" (49 CFR 383.111(a)(16)). It has three parts. The first covers what improperly secured cargo can do, the driver's responsibilities, and the federal, state, and local rules. The second is weight distribution, and the third is the principles and methods of securement.

The responsibility is personal. A motor carrier may not let you drive unless you can judge whether the cargo is properly placed, distributed, and secured, and you know how to secure it (391.13). You may not drive unless the cargo is secured under the federal rules, the doors, tarps, and spare tire are fastened, and nothing blocks your view or your access to emergency equipment (392.9(a)). The manual adds that this holds whether or not you loaded the truck.

The rules here come from the eCFR, current as of October 26, 2026. The federal securement rules sit in Part 393, Subpart I (393.100 to 393.136); the general sections used below, 393.106 and 393.110, were last amended in 2006, and no FMCSA rule or proposal published through October 2026 would change them, so they apply to 2027 tests and trips as well. The manual material follows Section 3 of Washington's CDL guide, a public copy of the model manual that state manuals follow.

Weight terms, worked on an original load

Ratings and scale weights answer different questions. Ray, a fictional driver, pulls a flatbed. His tractor's GVWR is 50,000 pounds, the trailer's is 46,000 pounds, and the tractor's label shows no GCWR, so the GCWR is the sum of the two ratings: 96,000 pounds. That rating, plus a towed unit rated over 10,000 pounds, makes this a Group A combination (383.91(a)(1)).

At the scale, loaded, the rig weighs 11,600 pounds on the steer axle, 33,400 pounds on the drive tandem, and 31,000 pounds on the trailer tandem: a gross combination weight of 76,000 pounds. Whether each axle is legal depends on the limits where Ray drives. The manual notes that states set maximum weights, often with a bridge formula that allows less weight on axles spaced close together. For the license class, the ratings are what normally count, although the federal definition of a commercial vehicle uses the actual weight when it is higher than the rating (383.5). The scale tickets decide whether the load is legal and balanced. Ratings versus weights is a General Knowledge staple, and 207 General Knowledge questions with explanations are planned for full CDL prep.

Center of gravity and balance

Where the weight sits matters as much as how much there is. The manual makes four points:

• A high center of gravity makes the vehicle easier to tip over, especially in curves and swerves, and on a flatbed it makes the load more likely to shift to the side or fall off. Keep the load low and put the heaviest items under the lighter ones.
• Too much weight on the steering axle makes steering hard and can damage the axle and tires.
• Too little weight on the front axle, from weight shifted too far back, can make the steering axle too light to steer safely.
• Too little weight on the drive axles means poor traction, so the drive wheels spin easily, and in bad weather the truck may not be able to keep going.

Overloading makes all of this worse: slow climbs, too much speed on downgrades, longer stops, and brakes that can fail from overwork. The manual adds that a legal maximum load may still be unsafe in bad weather or mountains, and that dry bulk, hanging meat, and livestock need extra care because they can shift on their own.

Blocking, bracing, and tie-downs in principle

Federal rules in Part 393, Subpart I require cargo to be firmly immobilized or secured by structures of adequate strength, dunnage or dunnage bags, shoring bars, tie-downs, or a combination of these (393.106(b)). Anything likely to roll must be held by chocks, wedges, a cradle, or something equivalent (393.106(c)(1)).

• Blocking sits against the front, back, or sides of the cargo, fits snugly, and is fastened to the deck so the cargo cannot slide.
• Bracing runs from the upper part of the cargo to the floor or walls.
• Tie-downs hold cargo on flatbeds and open trailers, and can matter in closed vans too. The total working load limit of the tie-downs securing an item must be at least half the item's weight (393.106(d)). A tie-down that runs from one side of the vehicle, over the cargo, to the other side counts at its full rating. One that runs from the vehicle to an anchor point on the cargo, or over the cargo and back to the same side, counts at half its rating.
• A front-end header board protects you if the cargo slides forward in a crash or hard stop.
• Covers protect people from spilled cargo and the cargo from weather. Check them in the mirrors as you drive, because a flapping cover can tear loose.

How many tie-downs: the manual's shortcut and the federal rule

This is one place where the manual and the regulation give different answers, so know both.

The manual's shortcut is at least one tie-down for every 10 feet of cargo, and never fewer than two, however small the item. The federal rule depends on length, weight, and whether the item is blocked against moving forward (393.110):

Work it on a 16-foot, 3,000-pound bundle of plastic conduit on Ray's flatbed. If nothing blocks it from sliding forward, the federal minimum is two tie-downs for the first 10 feet plus one for the remaining 6 feet: three. Pushed up against the header board, it needs one for each 10 feet or fraction: two. The manual's shortcut gives two either way. Then check the strength: the tie-downs' total working load limit must reach at least 1,500 pounds. Three straps rated at 1,000 pounds each, run side to side over the bundle, count at full value, for a total of 3,000.

Use the manual's version for the knowledge test. Washington's DOL, for example, says its guide contains all the information needed to pass the test (as checked on October 28, 2026). On the road, the federal rule applies, and it can require more tie-downs. Commodity-specific rules in 393.116 to 393.136, such as those for logs, metal coils, and heavy equipment, take precedence over the general rules where they add requirements (393.106(a)), and machinery or structural items that must be fastened by special methods are exempt from the count (393.110(d)). Because the manual and the regulation give different answers here, flashcards for numbers with their conditions are planned for full CDL prep, so you can keep the test version and the road version apart.

When to inspect and recheck cargo

1. Before the trip: as part of the inspection, confirm the truck is not overloaded and the cargo is balanced and secured. If it carries hazardous materials, check the papers and placards.
2. Within the first 50 miles: inspect the cargo and its securement devices, and adjust or add devices as needed (392.9(b)(2)).
3. During the trip: reexamine the load whenever you change duty status, after 3 hours of driving, or after 150 miles, whichever comes first (392.9(b)(3)). The manual adds a check after every break.

Here is that schedule on one run. Ray leaves the yard at 5:00 a.m. and averages about 55 mph on the interstate. He reaches 50 miles a little before 6:00, so his first check has to happen by then. Counting from that check, at 55 mph he will cover 150 miles in about 2 hours and 45 minutes, before 3 hours are up, so the mileage is what makes his next check due, unless he changes duty status sooner, for example by going off duty for a break. The free CDL practice questions include a flatbed securement-timing item, with a reason given for each option.

Sealed loads are the exception. The inspection duties in 392.9(b) do not apply to a driver ordered not to open a sealed vehicle, or to a load packed so that inspecting it is impracticable (392.9(b)(4)). The manual adds that you still check the gross and axle weights. Containerized loads must be secured like any other cargo.

Cargo checks are part of every inspection, so continue with the vehicle inspection guide and the rest of the 20 General Knowledge areas. The 50-mile, 150-mile and 3-hour checks are one of the flashcard drills planned for full CDL prep.