Louisiana CDL DMV Knowledge Test Class A 2

Drowsy driving is most common during the night because people are naturally prone to be less alert in the hours during which they are normally asleep. If you must drive at night, take every precaution to prevent fatigued driving.

It is important for you to be aware of your surroundings at all times. To do this, regularly check your mirrors. You should make a particular point of checking your mirrors when merging, changing lanes, turning, and performing tight maneuvers.

After starting a vehicle's engine, the oil pressure should come up to a normal level within seconds. Do not operate a vehicle if it has oil pressure that is low, dropping, or fluctuating.

The body removes alcohol at a fixed rate. The more alcohol consumed, the longer it will take for the body to remove the alcohol from its system.

When driving at dawn, at dusk, or in inclement weather, you should use your headlights on their low beam setting to increase your visibility.

The vehicle inspection test will include a check of the oil level. You must show that it is within a safe operating range.

Spring brakes do not work on all axles. If your vehicle's spring brakes activate due to low pressure in an air brake system, your vehicle will need a longer distance to stop than usual, especially if you are carrying a heavy load.

The tire load, or the maximum safe weight that a tire can carry at a given pressure, is stated on the side of each tire.

Good drivers look down the road at least 12 to 15 seconds ahead of their vehicles. This makes it possible to identify hazards early, when drivers are more likely to have time to respond appropriately.

When making mirror checks, you should look at the mirrors fairly quickly. If you spend too much time looking in a mirror, you may travel a substantial distance down the road without seeing what is coming up ahead.

If you are convicted of any traffic violations while driving any vehicle, you must notify your employer within 30 days of the conviction. This rule excludes parking violations.

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

Some air brake systems include an evaporator that introduces alcohol into the system. The alcohol can help prevent ice from forming within the system.

Rust around wheel nuts can indicate that the nuts are loose. If you find rust near the wheel nuts, check their tightness before beginning to drive.

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.

Wheels or rims that have had welding repairs are never safe for use.

When inspecting a tractor/trailer coupling, look into the fifth wheel gap and make sure the locking jaws are fully closed around the kingpin.

While driving, spring brakes are generally held in place by air pressure. If the air pressure gets low enough, the springs will activate the brakes.

If your vehicle begins to hydroplane, you can regain control by releasing the accelerator and pushing in the clutch.

When inspecting your vehicle, you should check the wiper blades for damage, stiff rubber, and proper securement.

Always signal before turning or changing lanes to ensure that other drivers are aware of your intentions.

One way to know when it is time to shift gears is to learn your vehicle's operating rpm range. You should shift up when your engine reaches the top of that range. You can also learn which speeds each gear is good for and shift up based on your speedometer.

When braking, push the pedal down gradually to ensure that the vehicle comes to a smooth, safe stop.

After a tire has been changed, you should stop a short while later to recheck the tightness of the lug nuts.

When approaching a long downgrade, you should shift into a lower gear then use proper braking techniques. Using the brakes alone could cause them to overheat and fail. The braking power of the engine, which is maximized by being in a lower gear, will be the principal way of controlling your speed on a downgrade.

In newer vehicles with air brakes, the parking brake is controlled by a yellow, diamond-shaped knob. The driver should pull the knob outward to apply the parking brakes and push the knob inward to release them.

The low air pressure warning signal must activate before the air supply pressure drops below 55 psi in the air tank. If the warning signal does not turn on when being tested during an inspection, the vehicle is not safe to drive.

It is the driver's responsibility to inspect their cargo; recognize overloading or poorly balanced weight; know that the cargo is properly secured and does not obscure the driver's view; and know that the cargo does not restrict access to emergency equipment. The driver is responsible for their cargo even if they were not the one who initially loaded and secured the cargo.

During the vehicle inspection test, you will be required to do a complete inspection of your vehicle. During this inspection, you must explain to the examiner what you are inspecting and why you are inspecting those items.

Missing clamps, spacers, studs, or lugs are dangerous, as are mismatched, bent, or cracked lock rings. Be sure your tires and rims are in good condition before operating your commercial motor vehicle.

There are several reasons why driving at night is more difficult than driving during the day. It is more difficult for drivers to see hazards, the glare of headlights can affect drivers' vision, and there are more fatigued drivers on the road.

When checking the tires as part of a pre-trip inspection, make sure the tires have sufficient tread. There should be at least 4/32 of an inch of tread in every major groove of the front tires, and at least 2/32 of an inch of tread depth on the other tires. Tire sizes should not be mismatched.

When parking on a level surface, you should use wheel chocks. If the vehicle is not equipped with spring brakes, this is essential to prevent the trailer from moving.

After changing a tire, you should stop a short distance later to recheck the tightness of the tire's lug nuts.

For your own safety, when placing reflective warning triangles, you should carry them between your body and the oncoming traffic.