Arizona CDL DMV Knowledge Test Class A 1

Fatigued drivers are slower to see or react to hazards than drivers who are not fatigued. Drivers are impaired in their ability to make critical decisions when they are driving drowsy.

A modulating control valve allows a driver to gradually apply spring brakes. In equipped vehicles, the valve is controlled by a lever located on the dashboard.

It is essential that you are aware of what is surrounding your vehicle at all times. You should make a habit of regularly checking your mirrors while driving.

Never push down the brake pedal while the spring brakes are activated. The combined force of springs and air pressure could damage the brakes.

In an air brake system, the air storage tanks hold compressed air to be used by the brakes. The number and size of air tanks varies among vehicles.

Alcohol impairment can begin with the first drink consumed. It is both illegal and dangerous to operate a motor vehicle while impaired by alcohol.

Because air takes time to flow through the air lines to the brakes, air brakes cannot begin working instantly. There is often a brake lag of at least one-half of a second between the moment the brake pedal is pressed and the moment the brakes begin to work.

Because air pressure increases with temperature, you should pay special attention to the tire mounting and pressure when traveling in hot weather.

If water and compressor oil are left to build up in an air brake system, the system can be damaged. Air storage tanks are equipped with drains to allow this accumulation to be removed. Manually controlled drains should be operated at the end of each day of driving.

Most states have an Implied Consent Law, which means that by driving a vehicle on the state's roads, you have agreed to undergo a drug or alcohol test if a police officer asks you to do so. If you refuse to submit to a test, you will lose your operating privileges. Make sure you are aware of the laws for every state in which you drive.

On many vehicles, multi-speed rear axles and auxiliary transmissions are used to provide extra gears.

On flatbed trailers and trailers without sides, cargo must be tied down. There should be at least one tie-down for every 10 feet of cargo. Regardless of the size of the cargo, at least two tie-downs must be used.

Vehicles equipped with Anti-Lock Braking Systems (ABS) have yellow malfunction lights to indicate issues in the braking system.

To ensure that your vehicle does not roll backward when beginning to move after a stop, you should partly engage the clutch before removing your right foot from the brake pedal.

An operator should drive with care when transporting a cargo of hanging meat. Such a load is unstable, both because it has a high center of gravity and because the swinging of the meat can affect the driver's handling of the vehicle.

All commercial motor vehicles are required to be equipped with the proper emergency equipment. This may include spare electrical fuses; three red reflective triangles, six fuses, or three liquid burning flares; and at least one properly charged and rated fire extinguisher.

Overloading a vehicle can have negative effects on steering, braking, and speed control. Learn to recognize when cargo is overloaded or poorly balanced.

Driving in fog is always dangerous and should be avoided entirely if at all possible. If you must drive in fog, be sure to turn on your low beam headlights and fog lights, even during the daytime.

Cargo should be restrained by at least one tie-down for every 10 feet of cargo. However, all cargo should have at least two tie-downs, no matter the size of the cargo.

B:C fire extinguishers are designed to work on electrical fires and burning liquids. Don't pour water on an electrical fire.

Truck tractors with air brakes built on or after March 1, 1997, and other vehicles with air brakes built on or after March 1, 1998, must be equipped with anti-lock brakes.

To avoid hitting vehicles behind you, you must ensure that your vehicle will not roll backward when you start moving forward from a stopped position.

It is important to observe other drivers' actions and identify clues that a person could be driving impaired. Drivers who have had too much to drink, are sleepy, are on drugs, or are ill can present hazards to other drivers. One sign that a driver may be impaired is that they stop in inappropriate places, such as at green traffic lights.

Avoid being an aggressive driver by being realistic about your travel time, making allowance for delays, maintaining reasonable following distances, and not making hand gestures that could anger another driver.

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.

Texting while driving is even more dangerous than speaking on a phone while driving. In addition to being mentally distracting, texting is also physically distracting.

You must have a hazardous materials endorsement to drive a vehicle of any size that is used to transport defined classes of hazardous materials.

Do not use the brake pedal when the spring brakes are on. This could damage the brakes by subjecting them to the combined forces of springs and air pressure.

When driving in reverse, it is always recommended that a driver backs their vehicle toward its left side. This will allow the driver the best possible view of the rear of their vehicle.

On a slippery road, you must adjust your driving speed to fit conditions. Because it will take longer for your vehicle to stop on a slippery road than on a dry road, you should increase your following distance when conditions are slippery. Avoid driving in a way that requires you to change speeds frequently.

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.

You should stay in the right lane of a multilane road if your vehicle is being slowed down by a heavy load. Allow other vehicles to pass your truck using the left lane.

Cargo with a high center of gravity makes a vehicle more likely to tip over than cargo with a low center of gravity. For this reason, it is important that the weight of cargo be distributed as low as possible.

During a trip, you should regularly make checks to ensure that your vehicle is operating properly. Check the instrument panel and gauges; look at your mirrors; and examine the tires, cargo, and lights. Use all of your senses and be alert for anything that could be an early indication of trouble.

When checking your vehicle's pedals during a pre-trip inspection, you should ensure that there is nothing under or around the pedals that will obstruct their use. Make sure the pedals are in proper working condition and that the surfaces of the pedals are grooved, if applicable.