Cargo weight should be evenly distributed within a trailer to reduce the risk of a rollover. Do not place too much weight on one side of a trailer.

It is always important to have enough water and antifreeze in a vehicle's cooling system. Despite the name, antifreeze is beneficial to an engine even in hot weather.

While driving, you should continually scan the road to spot potential hazards in advance. Make emergency plans for how to deal with the hazards if they become dangerous.

Always apply the parking brake when leaving your vehicle.

A pre-trip vehicle inspection should be done in the same way every time. Consistency will help a driver learn all of the proper steps and decrease the possibility of the driver forgetting to inspect something.

Indicators of drowsiness while driving include your eyes closing or going out of focus by themselves, having trouble keeping your head up, and drifting between lanes.

When a combination vehicle is lightly loaded, it may have poor traction. It is very easy for wheels to lock up on lightly-loaded vehicles when they are being stopped.

During the vehicle inspection test, you will be asked to do a complete inspection of your vehicle. You will need to explain what you are inspecting and why.

It is important to know the maximum air loss rate that is safe for your specific vehicle. A single vehicle with air brakes should have a leakage rate no higher than 3 psi in a minute during an applied leakage test.

A trailer may swing out and strike other vehicles if its wheels lock up. This is especially likely with lightly-loaded trailers.

A large vehicle may need to swing right to make a left turn. If an intersection has two left turn lanes, the driver should choose the righthand land to begin their turn.

Retarders are mechanisms in some vehicles that help slow the vehicle and reduce the need for braking. The four basic types of retarders are exhaust, engine, hydraulic, and electric.

During a trip, you should regularly monitor the instruments, gauges, meters, and mirrors. Check the tires, cargo, and lights for signs of trouble.

Backing is always dangerous because it is impossible to see everything that is behind your vehicle. Only drive in reverse if it is absolutely necessary.

Before driving a vehicle with a dual air brake system, you should wait for the air compressor to build up at least 100 psi in both the primary and secondary systems.

While regular mirror checks should be part of your normal driving routine, checking your mirrors is especially important when turning, changing lanes, merging, and performing tight maneuvers.

When performing a visual check of coupling devices, you should make sure there is no space between the upper and lower fifth wheel. Ensure that the locking jaws are securely closed around the kingpin.

Leaks in an exhaust system are extremely dangerous because they may allow toxic fumes into the cab or sleeper berth, endangering drivers and passengers.

If you must drive in reverse, you should first walk around your vehicle to look at the path of travel and check for obstacles. Because mirrors have blind spots, you cannot rely exclusively on them. It is recommended to use a helper whenever possible.

Driving at night is more dangerous than driving during the day because hazards become more difficult to see in the dark.