North Dakota CDL DMV Knowledge Test Class A 1

Front-end header boards, also known as "headache racks," protect the driver from cargo moving in the event of a crash or emergency stop.

If an Anti-Lock Braking System (ABS) is not working, the vehicle's basic braking functions are still intact. The driver should continue to drive and brake in a normal fashion.

You should be cautious when you are near people who are not paying attention to the road. Be wary of drivers who are engaged in conversation with passengers, children near the road, and road workers.

In a dual air brake system, if one of the air systems gets very low on pressure, either the front or rear brakes will not be operating fully. You should bring your vehicle to a safe stop and have the air system repaired.

Regardless of who has loaded cargo onto a vehicle, the driver is responsible for the safety of the cargo.

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.

Commercial vehicles should always carry the proper emergency equipment. Be sure your vehicle is equipped with at least one fire extinguisher; spare electrical fuses, unless the vehicle is equipped with circuit breakers; and warning devices for parked vehicles, such as warning triangles, fuses, or liquid burning flares.

It is important to communicate your intentions to others on the road. Make sure to signal before turning or changing lanes, even if no other vehicles are nearby.

Spring brakes come on automatically when air pressure drops to an unsafe psi level. Instead of waiting for the spring brakes to automatically activate, you should safely exit the road as soon as you notice the low pressure warning signal and bring your vehicle to a stop while you are still able to control the brakes.

A vehicle's total stopping distance is made up of perception distance, reaction distance, brake lag distance, and braking distance. With all of these factors included, an air brake-equipped vehicle traveling at a speed of 55 mph under ideal driving conditions will need approximately 450 feet to come to a complete stop.

When driving under foggy conditions, lights cannot be taken as a reliable indication of where the road is. The lights may be coming from a vehicle that has pulled off the road.

An air compressor governor will stop the compressor from pumping air once the air tanks are at an air pressure level of 125 psi. This air pressure level is referred to as the "cut-out" level.

Driving at excessive speeds is a major cause of fatal crashes. Never drive above the posted maximum speed limit and adjust your speed to fit conditions.

If you aren't sure that you have space for your vehicle to safely fit underneath an overhead object, slow down and seek an alternate route if possible.

If you think the road surface may be becoming icy, you can check for ice on your vehicle by opening the window and feeling the front of the side mirror, mirror support, or antenna. If ice has formed on any of these items, the road is likely becoming icy as well.

The adjustment of your mirrors should be checked prior to the start of all trips. Adjust your mirrors as needed.

Hazardous materials must be diamond-shaped and a size of at least 10 ¾ square inches.

If you encounter an aggressive driver, the most important thing to do is get out of their way, if possible. Do not provoke the driver by challenging them or making eye contact, and do not let yourself be provoked by rude gestures they might make.

Using the brakes after a tire failure could cause you to lose control of your vehicle. Unless you're about to hit something, stay off of the brake until the vehicle has slowed sufficiently.

It takes a longer distance to stop a vehicle on a slippery road than it does on a dry road. Use caution when driving under conditions that could cause a road surface to become slippery.

On flatbed trailers and trailers without sides, cargo must be tied down. There should be at least one tie-down for every 10 feet of cargo. Regardless of the size of the cargo, at least two tie-downs must be used.

To travel safely, it is essential that you know what is happening on all sides of your vehicle at all times. Check all mirrors frequently while driving.

It is important to observe other drivers' behaviors and identify clues that indicate when 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. A person driving with their window open in cold weather may be impaired.

Stay aware of upcoming obstacles and hazards by consistently watching the road at least 12 to 15 seconds ahead of your vehicle. When traveling at highway speeds, this is equivalent to about a quarter of a mile.

Drivers with blocked vision may pose hazards to others on the road. Examples of such drivers include those who haven't scraped ice off of their windshields; those driving vehicles loaded with large items blocking the windows; and those who are driving rental trucks without being used to the limited rear visibility of a truck.

Cargo must be properly balanced so that there is neither too little nor too much weight on the front or rear axles. Improperly balanced cargo can damage a vehicle and affect the handling of a vehicle.

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.

Defects in an exhaust system are very dangerous because they can cause poisonous fumes to enter the cab or sleeper berth.

In rainy weather, roads are often at their most slippery when the rain first begins to fall. Fresh rainwater mixes with oil and grease on the road to form a slick film. As the rain continues, this mixture will eventually wash away.

A modulating control valve allows a driver to gradually apply spring brakes. In equipped vehicles, the valve is controlled by a lever located on the dashboard.

Check your engine during the pre-trip inspection. After starting the engine, you should listen for unusual noises.

Before driving a vehicle with a dual air brake system, allow time for the compressor to build up pressure to at least 100 psi in both systems.

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.

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

Before driving a vehicle with a dual air brake system, you must allow the air compressor time to build up at least 100 psi of air pressure in both the primary and secondary systems.