Mississippi CDL DMV Knowledge Test Class A 1

Spring brakes will activate in a vehicle with air brakes if the pressure in the air system becomes too low. A heavily loaded vehicle will take a long time to stop when using only the spring brakes because the spring brakes do not work on all axles.

Most heavy-duty vehicles use dual air brake systems. A dual air brake system consists of two separate air brake systems, connected by a single set of brake controls. Each system has its own air tanks.

The air compressor of an air brake system is connected to the engine through gears or a v-belt. The compressor may be air-cooled or cooled by the engine cooling system.

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.

Air brakes consists of three separate braking systems: the service brake system, the parking brake system, and the emergency brake system.

The suspension system keeps a vehicle's axles in place. Damaged suspension parts, such as leaking shock absorbers, may be potentially dangerous defects on a vehicle.

When approaching a curve during the on-road driving skills test, you must reduce your speed sufficiently before entering the curve so that you do not need to further brake or shift in the curve. Keep the vehicle in its lane and continue to check for traffic in all directions.

When driving a tractor-trailer combination that is equipped with an Anti-Lock Braking System (ABS), you should brake in the same manner that you would if the vehicle was not equipped with ABS.

When operating a new vehicle, you should familiarize yourself with its features and equipment before getting behind the wheel.

Wheels or rims that have had welding repairs are not safe for use. They should be replaced before the vehicle is taken on the road.

In the event of a crash, a safety belt keeps the driver of a commercial motor vehicle securely positioned behind the steering wheel. This both protects the driver from injury and makes it easier for them to maintain control of the vehicle.

A driver is allowed to exit their vehicle to check its position during any basic vehicle control skills test exercise. This action is called a "look." During the straight line backing exercise, a driver may not exceed one look. During any other exercise, a driver may not exceed two looks.

Always downshift before beginning to drive downhill. Forcing an automatic transmission into a lower gear at a high speed could damage the transmission and also lead to a loss of ability to engine brake. Drive at a speed that will allow you to control your vehicle without overusing your brakes. When determining a safe speed to drive, you should take into account the steepness of the grade, the length of the grade, the weight of your vehicle, road conditions, and weather conditions.

To avoid becoming fatigued on a long trip, you should take a break after every 100 miles or two hours of driving. Driving through the night, or during any other time when you would normally be asleep, raises the danger of fatigue.

A vehicle's headlights should be clean during trips. This will ensure that the lights can provide as much light as possible, helping the vehicle to be seen.

Always watch for hazards on the road ahead. Doing this will allow you time to react to hazards before meeting them.

Steering wheel play of more than 10 degrees (about two inches of movement at the rim of a 20-inch steering wheel) can make it difficult to steer.

To reduce the chances of becoming fatigued on a long trip, a driver should stop for a break at least once every two hours or 100 miles driven.

To avoid engaging in dangerous and aggressive driving behavior, you should relax and accept any delays that arise throughout a trip. To help avoid the stress of arriving late to a destination, plan for likely delays when planning your drive.

You should reduce your speed by about one-third when driving on a wet road. It can be difficult to stop or turn when operating on a slippery surface, so you must adjust your speed to drive safely under such conditions.

If you are asked to complete an offset back/right parking maneuver, you should first pull straight forward, then back up to the right. Your vehicle must be parked completely within the boundaries of the parking space.

When a brake pedal is pressed and the S-cam is turned, the S-cam presses the brake shoes against the inside of the brake drum. This causes friction and will cause the vehicle to slow.

When using your turn signals, you should signal well before the turn or lane change, signal continuously throughout the turn or lane change, and cancel the signal after you have completed your move.

While driving, regular mirror checks are essential to remaining aware of the traffic around you. Mirrors are also essential to helping you spot possible problems on your own vehicle.

In the event of an engine fire, you should turn off the engine as soon as possible. Do not open the hood if you can avoid it. Shoot foam through the louvers or from the vehicle’s underside.

During the on-road driving test, you must listen to and follow the directions given by the examiner. They will never ask you to drive in an unsafe manner.

Foundation brakes are used at each wheel. The most common type is the S-cam drum brake.

If being shipped on a flatbed trailer or on a trailer without sides, cargo must be securely tied down to keep it from shifting or falling off while the vehicle moves.

It is important that the driver of a CMV always downshifts before entering a curve.

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.

In a tractor-trailer combination, if the tractor is equipped with an Anti-Lock Braking System (ABS) but the trailer is not, the ABS will still improve the driver's steering control. The driver should keep an eye on the trailer and let up on the brakes if the trailer begins to swing out.

If you are not certain that your vehicle will fit under overhead objects, you should slow down and take a different route, if possible.

Black ice is a layer of ice that is thin and clear enough for the road to be visible through it. This makes the road look as if it is merely wet.

Proper loading of cargo is essential for safety. Cargo that is not properly secured could fall off and cause death or injury. Excessive or inappropriate loading could damage a vehicle, and make it hard for a driver to steer safely.

A driver's seat should always be equipped with a seat belt. You must wear a seat belt at all times while operating a CMV.