Washington CDL DMV Knowledge Test Class B 2

When driving at dawn, at dusk, or in inclement weather, you should use your headlights on their low beam setting to increase your visibility.

When approaching your vehicle, you should check under the vehicle for fresh oil, coolant, grease, or fuel leaks. Spotting any of these before a trip is a cause for concern.

Many large CMVs are equipped with air brakes. An air braking system uses compressed air to operate.

Cargo with a high center of gravity makes a vehicle more likely to tip over than cargo with a low center of gravity. For this reason, it is important that the weight of cargo be distributed as low as possible.

There are two air brake systems in a dual air brake system. The systems share a set of brake controls, but each system has its own tanks, hoses, and lines.

Most drivers are the least alert at night, especially after midnight. Therefore, crashes due to fatigued driving are more likely at night than any other time of day.

When inspecting your tires, verify that there is at least 4/32 of an inch of tread depth in every major groove on the front tires, and tread depth of at least 2/32 of an inch on the other tires. Tires on the same vehicle should all be the same size.

If you must stop on the side of the road, make sure to use your four-way emergency flashers. This is particularly important at night.

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

A dual air brake system is made up of two separate air brake systems. The systems share a single set of brake controls, but each has its own air tanks, hoses, and lines. One system typically operates the regular brakes on the rear axle or axles while the other system operates the regular brakes on the front axle.

Be careful around pedestrians, joggers, and cyclists who are wearing headphones. They may be unable to hear your vehicle approaching and may do dangerous things because they do not know you are there.

Blocking is used in the front, in the back, and/or on the sides of a piece of cargo to keep it from sliding while the vehicle is in motion.

Before beginning a trip, it is important to check the brake drums during your walk-around inspection. It is unsafe to drive if any brake drum has a crack more than one half of the width of the friction area.

If you encounter an aggressive driver, you should not let yourself be provoked by any angry gestures they make toward you. Avoid making eye contact with the other driver and do not try to race them.

You should accelerate very gradually when driving under conditions that create poor traction.

A common cause of vehicle fires in the aftermath of an accident is the improper use of flares near spilled fuel. Use flares with caution.

To prevent a vehicle with manual transmission from rolling backward when you begin to move forward from a stopped position, you can partly engage the clutch before removing your foot from the brake pedal.

Tires should never have too much air pressure. Be sure to check your tires' air pressure with a gauge during inspections.

An Individual Vehicle Distance Record (IVDR) must include information about the distance traveled by a vehicle and the amount of fuel purchased. The required distance information includes the origin and destination points of the trip and the Vehicle Identification Number.

Roads are often especially slippery when it first begins to rain. Rainwater forms a slick film when mixed with oil and grease on the road surface that has not yet washed away.

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

Friction inside a brake drum is caused when the brake shoes and linings push against the inside of the drum. The friction in the drums will slow and stop the vehicle.

When turning on your vehicle's engine, the lights on the dash should come on and then turn off. If the ABS malfunction light stays on, the system is not working properly. In the case of a truck with a trailer, if the yellow light on the left rear of the trailer stays on once the engine has been started, the system is not working properly.

Backing a truck is always dangerous because the driver may not be able to see everything behind them. CMV operators should avoid backing whenever possible.

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.

The safety relief valve in an air brake system releases air if necessary to prevent pressure in the system from becoming too high. If the valve starts releasing air, there is something wrong. Have a mechanic fix the problem.

Before starting down a hill, decelerate and shift down into a gear that will allow you to control your vehicle without braking too hard. Using too much brake when driving downhill can cause the brakes to overheat, reducing the braking power.

When inspecting a vehicle with a dual air brake system, you should wait for air pressure to build from 85 to 100 psi in both the primary and secondary systems. This should take about 45 seconds.

Always apply the parking brake when leaving your vehicle unattended.

Be cautious when driving near people who are working on a disabled vehicle on the side of the road. They may be focused on the repair and not paying attention to nearby traffic.

A broken exhaust system can let poisonous fumes into a vehicle's cab or sleeper berth. Be sure to inspect your exhaust system for any loose, broken, or missing parts.

For your own safety, when placing reflective warning triangles, you should carry them between your body and the oncoming traffic.

If involved in a collision, you must stop immediately to tend to the injured and exchange information with all others involved. File a report with law enforcement within four days of any collision resulting in injuries or more than $1,000 in damage.

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.

Potential warning signs of fatigued driving include difficulty focusing; frequent blinking or heavy eyelids; yawning repeatedly or rubbing one's eyes; daydreaming; wandering or disconnected thinking; trouble remembering the last few miles driven; missing exits or traffic signs; having trouble keeping one's head up; drifting from one's lane; following a vehicle too closely; hitting a shoulder rumble strip; and feeling restless or irritable.