Commercial Driver’s License (CDL) · CDL Manual Chapters
Transporting Cargo Safely
On this page 6 sections
In 30 seconds
Cargo that shifts, spills, or overloads an axle can roll a truck, block a highway, or get you fined at a scale. Your job is to inspect the load before the trip and again along the way, keep the weight low, centered, and within limits, and hold everything down with the right number of tie-downs and covers. The driver, not the shipper, is the one the inspector and the law hold responsible.
Why this matters
The General Knowledge test asks about cargo inspection, weight limits, and tie-downs, and on the job you are legally responsible for a load being safe and legal even when someone else put it on the truck.
The college version
In normal terms
- Check the load before you leave, within the first 50 miles, and then every three hours or 150 miles.
- Keep weight low, spread evenly, and within the legal axle and gross limits.
- Use at least one tie-down per 10 feet of cargo, and never fewer than two, with cover where cargo could blow or spill.
Concepts in this outline
- Cargo inspection — Check the load before departure, within 50 miles, then every three hours or 150 miles, looking for loose, shifted, or overhanging freight.
- Weight distribution and balance — Stay within gross and axle limits, keep heavy items low and centered, and spread weight so no axle or side is overloaded.
- Securement devices, covers — Tie-downs at one per 10 feet and at least two, blocking, bracing, and header boards, plus tarps to stop spills and protect cargo.
Eli explains
The same idea, in plain words
Explain it like I’m 10
Think about packing a backpack for a long hike. Cargo inspection means checking the load before you leave. You check it again within the first 50 miles. Straps stretch and boxes settle once the truck moves. After that you check every three hours or 150 miles, whichever comes first. You also check at every break or change of duty status. Look for loose tie-downs, shifted freight, torn tarps, and anything hanging over the sides. In a sealed van you cannot see inside. You still confirm the weight and check the doors and seals.
Weight distribution is where the weight sits, not just how much there is. The gross vehicle weight rating is the most one loaded vehicle may weigh. The gross combination weight rating is the limit for the tractor and trailer together. Each axle has its own limit too. An axle is the bar that holds one set of wheels. So a legal total can still be illegal if too much sits on one axle. Too much weight in the back makes the front end light, and it wanders. Too much in the front overloads the steer tires. Keep it balanced.
Center of gravity is the spot where the weight balances. Put heavy books at the top of a backpack and it tips you over. A tall stack of heavy cargo turns the trailer into a lever that wants to tip in a curve. So heavy pieces go on the bottom, low and centered between the sides. Balance side to side matters too. If one side carries more, those wheels work harder and the truck stops crooked.
Securement devices hold the load where you put it. Tie-downs are chains, straps, and ropes. Together they must be strong enough to lift one and one-half times the cargo's weight. Use one tie-down for every 10 feet of cargo. Never use fewer than two, no matter how short the piece. Blocking is bracing set against the front, back, or sides so cargo cannot slide. Bracing runs from the top of the load down to the floor or walls so it cannot tip. Header boards, also called headache racks, protect the cab if the load slides forward in a hard stop.
Covers are tarps, and they do two jobs. They keep loose stuff like gravel and sand from spilling on other drivers, which many states require. They also protect the cargo from weather. Glance at the tarp in your mirror. A flapping edge means it is coming loose. Special loads have extra rules. Sealed trailers stay shut. Liquid tanks slosh. Hanging meat has a high center of gravity. Oversized loads need permits and escorts. Your state's CDL manual has the exact limits.
Worked example
Dolores picks up a flatbed load of 36-foot steel beams. Before she pulls out she confirms the scale ticket keeps her under the gross and axle limits, then walks the trailer. The beams sit low and centered, so the center of gravity stays where she wants it. At one tie-down per 10 feet she needs four, and she adds a fifth at the front where the beams stack. She checks that the header board is in place. Fifty miles down the road she pulls into a rest area, retightens two straps that have relaxed, and marks the time so she knows her next check comes at three hours or 150 miles. Nothing shifts the whole trip, and the scale inspector waves her through.
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