Fatigue and lack of alertness are major hazards when driving at night. Most people are the least alert at night, especially after midnight.

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

Hazardous materials placards must be at least 10 and three-quarter inches square.

When checking your mirrors, only look at them quickly. If you concentrate on one mirror for too long, you may travel a substantial distance down the road without being aware of what is ahead, missing important information about upcoming hazards.

If you must drive in reverse, you should first walk around the vehicle to check for hazards in your path of travel. Make frequent use of the mirrors on both sides of your vehicle while backing. Always back up as slowly as possible.

A pre-trip inspection should include a check of components in the engine compartment, including a check of the engine oil level.

A bus that is disabled while passengers are on board should not be towed or pushed, unless it is absolutely necessary. If needed, the bus should be towed or pushed only as far as the nearest safe location for the passengers to be discharged.

The adjustment of mirrors must be checked prior to the start of any trip.

Pre-trip inspections should be conducted in the same way every time. This will reinforce the steps, making it less likely that you will forget to inspect something important.

During the external inspection portion of the pre-trip vehicle inspection test, you must verify that the steering box is securely mounted and not leaking.

When turning quickly to avoid colliding with a hazard in the roadway, you should always keep both hands on the steering wheel. You must have a firm grip on the wheel to be able to turn quickly.

A vehicle should be inspected before every trip to help ensure that any small mechanical issues are caught before they become more serious problems. It is better to discover a problem with your vehicle before a drive than after the drive has begun.

Using the brakes after a tire failure could cause you to lose control of your vehicle. Unless you're about to hit something, stay off of the brake until the vehicle has slowed sufficiently.

Speeding up too quickly on a road with poor traction could cause a driver to lose control of their vehicle. In conditions that cause poor traction, a driver should accelerate especially smoothly and gradually.

Bridges will generally freeze before other parts of the roadway. Be careful on bridges when temperatures are around the freezing point.

A hot, poorly-ventilated area can make a person sleepy. Opening a window, opening a vent, or using the air conditioning can help keep the cab cool and reduce the risk of fatigue.

When inspecting your brakes, you should verify that the shoes and pads do not have any oil, grease, or brake fluid on them.

Focusing on your mirrors for too long can be dangerous because you will have traveled a substantial distance without looking at the road ahead.

You should approach every railroad crossing with the expectation that a train is coming. Do not rely on signals or your hearing to reliably tell you if a train is present. Always slow down when approaching a crossing. Never try to race a train.

As a part of earning your CDL, you will have to pass an inspection test and demonstrate that your vehicle is safe for operation. During the vehicle inspection test, you will have to walk around the vehicle and point to or touch each item and explain to the examiner what you are checking and why. You will not have to crawl under the hood or under the vehicle.