In an air brake system, the air compressor governor controls when the air compressor pumps air into the air storage tanks.

Cargo covers should not flap in the wind. They could tear loose, not only uncovering the cargo but also blocking the views of drivers.

The Gross Vehicle Weight (GVW) is the total weight of a single vehicle plus its load. The Gross Vehicle Weight Rating (GVWR) is the maximum combined weight of a vehicle and its cargo that is permitted and specified by the manufacturer.

The purpose of an Anti-Lock Braking System (ABS) is to prevent wheels from locking up during hard applications of the brakes, especially on slippery surfaces.

Bridges usually freeze before the rest of the road. You should be especially careful when crossing bridges if the temperature is near the freezing point.

When inspecting a vehicle's suspension, you should look for broken or missing leaves in the leaf springs. Any defect of this kind is dangerous. If one-fourth or more of the leaves are missing from any leaf spring, the vehicle must be put out-of-service.

When connecting a converter dolly to the rear trailer, make sure the trailer height is correct. It should be slightly lower than the center of the fifth wheel so that the trailer is raised slightly when the dolly is pushed under.

When inspecting a vehicle equipped with power steering, check the hoses, pumps, and fluid level. Be sure to check for and repair leaks before operating the vehicle.

When backing with a trailer, turn the top of the steering wheel in the direction opposite of where you want to go. Once the trailer begins turning, you should then switch the direction of the steering wheel to follow the trailer.

Many large vehicles have curved, convex mirrors. Convex mirrors allow drivers to see a wider area than flat mirrors. However, they also make objects seem smaller and farther away than they really are.

If the interior of your cab is too bright when you are driving at night, you may have difficulty seeing things outside. Keep the interior light off and adjust your instrument lights to the lowest possible level that still allows you to easily read the gauges.

If you use a helper while backing your vehicle, they should stand near the back of the vehicle in a place where they are visible to you. Before backing, work out a set of hand signals that both you and your helper understand. Agree on a signal for "stop."

When crossing or entering traffic, bear in mind the size of your vehicle and the distance it will need to accelerate. Wait for a gap in traffic that is large enough to accommodate your vehicle before you begin to accelerate. Remember that you will need more room to accelerate if your vehicle is heavily loaded. Before crossing a road, be sure that you can get all the way across without interfering with traffic.

Mandatory emergency equipment includes: at least one fire extinguisher; spare electrical fuses (unless the vehicle is equipped with circuit breakers); and warning devices for parked vehicles (such as reflective triangles).

You should never rely only on warning signals to alert you to an approaching train. Never try to race a train to a crossing. If there are multiple tracks at a crossing, be sure to check all tracks in both directions before starting to cross.

Most heavy vehicles with manual transmissions require double clutching to change gears. A driver should release the accelerator, push in the clutch, and shift into neutral at the same time. After releasing the clutch and allowing the vehicle to change to the necessary speed, the driver should push in the clutch, shift gears, then simultaneously release the clutch and accelerate.

Air brakes consists of three separate braking systems: the service brake system, the parking brake system, and the emergency brake system.

Suspension systems receive weight capacity ratings, given by the manufacturers.

If a federal or state inspector judges a CMV to be unsafe, they may put it out-of-service until it is fixed.

Loads that are over-length, over-width, and/or overweight may require special permits. Such vehicles are usually only allowed to be driven at certain times.