Oregon CDL Permit Test - Knowledge Test Class A

Defects in an exhaust system are very dangerous because they can cause poisonous fumes to enter the cab or sleeper berth.

When checking your tires as part of a pre-trip inspection, it is important to verify that the tire pressure is neither too low nor too high.

Compressed air in an air brake system usually contains a certain amount of water and compressor oil. The water and oil can damage the brakes if left to accumulate in the system. Tanks must be drained regularly to remove this build-up.

Distractions while driving can be physical (such as reaching for an object), mental (such as making conversation with a passenger), or both (such as holding a phone to send texts).

A vehicle is vulnerable to tipping over if its center of gravity is too high. To prevent this, you should distribute the weight of your cargo evenly and as low as possible.

Splitting driving responsibilities with a second driver lowers the chance that either of you will drive while fatigued. You can also reduce the risk of fatigue by avoiding heavy foods and keeping the interior of the cab cool.

When driving during the winter, it is especially important to make sure the coolant and antifreeze are at safe levels.