Louisiana CDL DMV Knowledge Test Class A 1

Increasing your vehicle's speed will increase your vehicle's striking power and braking distance. Doubling your vehicle's speed from 20 to 40 mph will quadruple its braking distance.

The function of an Anti-Lock Braking System (ABS) is to help prevent wheel lockup during hard braking. With ABS equipped on your vehicle, you should drive and brake in the same manner that you would without it.

Foundation brakes are used on each wheel of a CMV. The most common type of foundation brake is the s-cam drum brake.

An alcohol evaporator can help prevent ice from building up in an air brake system. In cold weather, the evaporator should be checked and refilled every day.

Rust around wheel nuts may mean that they are loose. Check the tightness of the nuts if you see any rust in the area.

Backing a commercial motor vehicle is always dangerous because you cannot see everything behind you. When backing, make frequent checks of the mirrors on both sides of the vehicle.

Whenever you pass another driver, bicyclist, or pedestrian, you should assume as a precaution that they do not see you.

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.

To avoid engaging in aggressive driving behavior, it is helpful to give other drivers the benefit of the doubt. Assume that they have valid reasons for what they are doing and don't take their actions personally.

Many large vehicles have curved, convex mirrors. Convex mirrors allow drivers to see a wider area than flat mirrors. However, they also make objects seem smaller and farther away than they really are.

If a heavy load prevents your vehicle from keeping up with the speed of other traffic, you should stay in the right lane.

In an air brake system, the air compressor governor controls when the air compressor pumps air into the storage tanks. It stops pumping if the pressure in the tanks becomes too high, and begins pumping if the pressure becomes too low.

If you must back up, it is safest to back toward the driver's side of the vehicle. This way, as the driver, you will have the best possible view of your path of travel.

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.

You should cover your cargo to protect people from the cargo if it spills, as well as to protect the cargo from the weather.

When approaching your vehicle before an inspection, make note of its general condition and ensure that it is not damaged or leaning. Look under the vehicle for fresh leaks of oil, grease, or fuel. Check around the vehicle for hazards to movement, such as people, other vehicles, or low-hanging wires or tree limbs.

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.

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.

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.

When driving, you should regularly check your mirrors, both to be aware of traffic and to check for problems on your own vehicle.

Parking brakes should be used whenever you park. If necessary, chock your wheels.

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.

In heavy traffic, it is safest to travel at the same speed as other vehicles. If two vehicles continue to drive in the same direction at the same speed, they cannot hit each other.

Anti-Lock Braking Systems (ABS) are compatible with air brakes and help a driver maintain control of their vehicle by preventing wheel lockup.

During the on-road driving test, you must not stop, change gears, pass another vehicle, or change lanes while any part of your vehicle is in a railroad crossing.

If you are not sure which kind of extinguisher should be used on a fire in your vehicle, particularly a hazardous materials fire, you should wait for the firefighters to arrive and allow them to extinguish it.

Passing parked delivery or postal trucks can be dangerous because the driver may be in a hurry and pull into traffic without warning, or may they suddenly step out of the vehicle without checking for other traffic.

Dry bulk tanks require special care to be driven, both because they have high centers of gravity and because the weight of the load can shift in transit.

Once you have begun to drive after a tire has been changed, you should stop after a short distance to recheck the tightness of the lug nuts.

When traveling at speeds under 40 mph, you should allow a minimum of one second of following distance for every 10 feet of your vehicle's length. At faster speeds, add at least one additional second.

When asked to make a turn during the on-road driving test, you must check traffic in all directions and use your turn signal.

Vehicles with ABS have yellow malfunction lamps to alert drivers when the braking systems are not working. Be sure you know where the malfunction lamp on your vehicle is before beginning a trip.

The heavier a vehicle is, the more the brakes will need to work to bring the vehicle to a complete stop.

Maximum axle weights are often set by a bridge formula, which sets a lower maximum weight for axles that are close together.

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.