Arkansas CDL DMV Endorsement Double 2

On newer vehicles, the trailer air supply control is an eight-sided red knob. It's used to control the tractor protection valve.

Air brakes consists of three separate braking systems: the service brake system, the parking brake system, and the emergency brake system. The service brake system applies and releases the brakes when you use the brake pedal while driving normally.

Cargo needs to be secured appropriately to prevent it from moving in transit. Cargo should be arranged to keep the vehicle's center of gravity low and well-distributed.

Operators driving too fast is a major cause of fatal crashes. You must continually adjust your speed to a rate that is safe for road and traffic conditions.

When parking a double or triple, be careful to park only in spots that allow you to pull forward when exiting. Do not choose parking spots that require you to exit by backing up.

Swerving out of the way of a hazard is sometimes safer than trying to stop before reaching the hazard. You can usually turn away from something more quickly than you can come to a complete stop.

To make a normal stop in an air-braked vehicle, push the brake pedal down and control the pressure so that the vehicle comes to a smooth, safe stop.

If a vehicle has anti-lock brakes on just one axle, the driver will still have more control during braking than they would without any anti-lock brakes.

Placards must be placed on the outside of vehicles carrying hazardous materials. They identify the specific class or classes of materials being carried and warn others of relevant hazards.

If you see a distracted driver, give them plenty of space and maintain a safe following distance.

Bobtail tractors are tractors that are not attached to any semitrailers. When operating a bobtail, you should be aware that stopping can be difficult and that it will take a longer distance to bring the bobtail to a complete stop than it would a tractor attached to a loaded semitrailer.

Brakes are particularly prone to getting out of adjustment if they are hot. Be sure to routinely check the adjustment of your brakes. For a vehicle to be safely controlled, all brakes must be properly functioning and adjusted.

After a vehicle is started, the warning lights and buzzers should go out after a few seconds. If the warning signals do not turn off, there may be something wrong with the vehicle.

A trailer may swing out and strike other vehicles if its wheels lock up. This is especially likely with lightly-loaded trailers.

To reduce the chances of driving distracted, you should avoid eating, drinking, or smoking while driving. Anything that diverts attention from the task of driving is a distraction.

When passing a pedestrian or another vehicle, you should assume that they don't see you.

Distracted drivers perceive hazards on the road more slowly than drivers who are focused, or they do not perceive hazards at all.

When connecting a converter dolly to a second or third trailer, the trailer height should correct. It should be slightly lower than the center of the fifth wheel.

Anti-Lock Braking Systems (ABS) are compatible with air braking systems. ABS helps maintain control of a vehicle and prevents the wheels from locking up during hard braking on slippery surfaces. ABS can still provide benefits even if is present on only one axle.

When inspecting your vehicle, you should check all belts for tightness and excessive wear. You should learn how much "give" is appropriate for each belt.