South Carolina CDL DMV Knowledge Test Class B 1

When backing with a trailer, begin by turning the steering wheel in the direction opposite of the turn. Once the trailer starts to turn, reverse the direction of the steering wheel to follow the trailer.

The suspension system holds up a vehicle and its load while keeping the axles in place. Defects in this system are extremely dangerous.

While regular mirror checks should be part of your normal driving routine, checking your mirrors is especially important when turning, changing lanes, merging, and performing tight maneuvers.

Air expands as its temperature increases, so air pressure in your tires is likely to increase when you are driving in very hot weather. Under such conditions, stop periodically to ensure that your tires are not at risk of blowing out or catching fire.

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.

A leaking exhaust system can introduce carbon monoxide, which is poisonous, into the cab or sleeper berth.

On long and/or steep downgrades, you should primarily use engine braking to control the speed of your vehicle. Use your brakes only as a supplement to this effect.

If your vehicle has air brakes, the air compressor drive belt should be checked before each drive. Check the tightness of the belt and verify that it is in good condition.

In an air brake system, the air storage tanks hold enough air for brakes to be used several times if the compressor stops working.

If you aren't sure that you have room for your vehicle to safely fit under an overhead object, you should slow down while approaching it. Seek an alternate route, if possible.

When inspecting a vehicle, you should verify that your dual tires do not come into contact with one another, or with any other part of the vehicle.

It is essential that you are aware of what is happening on all sides of your vehicle at all times. Scan the road ahead and make regular checks of the mirrors on both sides of your vehicle while you are driving.

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 transporting cargo on a flatbed trailer, you should use at least one tie-down for every 10 feet of cargo. Any cargo, no matter how small, should be restrained by a minimum of two tie-downs.

If you must stop on or by a one-way or divided highway, you must place a warning device 10 feet, 100 feet, and 200 feet to the rear of your vehicle.

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.

Before starting down a hill, be sure to switch into a low gear. Gravity will increase your vehicle's speed as you travel downhill.

The total stopping distance for vehicles equipped with air brakes is made up of four factors: perception distance, reaction distance, brake lag distance, and braking distance. When braking at a speed of 55 mph while driving on dry pavement, the brake lag can add around 32 feet to a vehicle's total stopping distance.

Under some driving conditions, it may not be safe to operate a vehicle at its full legal maximum weight. Keep this in mind when driving in poor weather or on mountainous roadways.

Passing an accident scene can be hazardous because the people involved in the accident may not be watching traffic, and the scene itself may distract other passing drivers. Ice cream trucks can create hazardous conditions because they attract children who may not pay attention to nearby vehicles. Shoppers near the roadway are often paying attention to stores, not passing traffic.

If there is enough water on the road, hydroplaning can occur at speeds as low as 30 mph. It is most likely if the tires' air pressure is too low or if tires' tread is worn.

Always apply the parking brake when leaving your vehicle unattended.

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

If your vehicle begins to hydroplane, do not apply the brakes. Instead, release the accelerator and push in the clutch. This will slow down your vehicle and help it regain traction.

Texting while driving is particularly dangerous because it is both a mental and physical distraction to the driver. In addition to diverting a driver's mental attention away from the road, texting requires a person to remove at least one hand from the vehicle's controls.

When driving, you should frequently check the mirrors on both sides of your vehicle.

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

After the engine is started, the warning lights and buzzers should deactivate immediately. The charging circuit warning, oil, coolant, and Anti-Lock Braking System (ABS) lights should all turn off.

You must sign the previous vehicle inspection report only if defects were noted and certified to have been repaired or not needing to be repaired.

The two basic reasons to cover cargo are to protect people from the cargo if it spills and to protect the cargo from weather conditions.

Before starting down a hill, be sure to switch into a low gear. Gravity will increase your vehicle's speed as you travel downhill.

Height warnings are often, but not always, posted on low bridges. If you are unsure if you will be able to clear an overhead object, go slowly.

The first step of a vehicle inspection is to review the last vehicle inspection report. Only sign the report if noted defects are certified to have been repaired.

In general, you should always use the parking brake when parking your vehicle. However, you should not apply the parking brake if your brakes are very hot or if your brakes are wet and temperatures are below freezing.

A pre-trip vehicle inspection should be done in the same way every time. Consistency will help a driver learn all of the proper steps and decrease the possibility of the driver forgetting to inspect something.