Massachusetts CDL DMV Knowledge Test Class B 1

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.

If you lose pressure in a hydraulic brake system, one appropriate response is to shift down into a lower gear. This will help slow the vehicle.

A convex mirror makes objects seem smaller and farther away than they actually are.

Commercial drivers are required by federal and state laws to inspect their vehicles before every trip. Regular inspections can help drivers identify issues before they become dangerous and costly.

Whenever you pass another driver, bicyclist, or pedestrian, you should assume as a precaution that they do not see you.

When inspecting a vehicle that is equipped with power steering, check the hoses, pumps, and fluid level. In particular, you should look for leaks in the hoses.

If there is a fire in your vehicle, the first thing you need to do is leave the road and stop. Park in an open area away from anything that could catch fire, such as plants or other vehicles. Do not pull into a service station.

During the basic vehicle control skills test, there is no penalty for an initial pull-up; however, an excessive number of pull-ups will count as errors.

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.

Mismatched, bent, or cracked lock rings are dangerous and should not be used.

A pre-trip inspection should be completed in the same way before every drive. Consistency will help you learn all of the proper steps and decrease the likelihood that you will forget to check something.

Intrastate commerce is defined as when you drive a CMV only within a single state, and the cargo you are carrying is not part of a trip that began or will end outside of the state.

Potential problems to check for when inspecting brakes include cracked drums; shoes or pads with oil, grease, or brake fluid on them; and shoes that are missing, broken, or worn dangerously thin.

Focusing on your mirrors for too long can be dangerous because you will have traveled a substantial distance without looking at the road ahead.

If a vehicle is carrying hazardous materials that require placarding, there must be identical placards placed on the front, rear, and both sides of the vehicle.

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.

Compressed air in an air brake system usually contains a certain amount of water and compressor oil. The water and oil can damage the brakes if left to accumulate in the system. Tanks must be drained regularly to remove this build-up.

Press the brake pedal down smoothly and gradually every time you slow or stop. The amount of brake pressure you need to apply depends on the speed of your vehicle and how quickly you need to stop.

Federal and state laws require drivers to inspect their vehicles before driving to ensure that they are safe to operate.

If you must drive slowly, you should warn drivers behind you by turning on your emergency flashers, as long as local law permits their use.

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

If a pre-trip inspection reveals anything unsafe about your vehicle, you must get it repaired. It is illegal to operate an unsafe vehicle.

If you need to make an emergency stop, you can use either the controlled braking method or the stab braking method. It's important to brake in a way that keeps your vehicle traveling in a straight line while still allowing you to turn, if necessary.

Because air takes time to flow through the air lines to the brakes, air brakes cannot begin working instantly. There is often a brake lag of at least one-half of a second between the moment the brake pedal is pressed and the moment the brakes begin to work. On vehicles with hydraulic brakes, the brakes work instantly when the pedal is pressed.

During the vehicle inspection test, you will need to show emergency equipment, including spare electrical fuses; three red reflective triangles, six fuses, or three liquid burning flares; and a properly charged and rated fire extinguisher.

To receive a hazardous materials endorsement, you must undergo a background check, which includes being fingerprinted.

You should never exceed the speed shown on a "Maximum Safe Speed" sign.

All air tanks on air-braked vehicles must have one-way check valves located between the air compressor and the first reservoir. This prevents air from flowing out in the event of a leak.

In an air brake system, the air storage tanks are equipped with drains to allow water and compressor oil to be removed. The water and oil can damage the brakes if left to accumulate in the system.

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

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.

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.

If the low air pressure warning signals activate, it is essential that you bring the vehicle to a safe stop while you are still able to control the brakes.

When making a right turn, avoid turning too wide to the left. If you must swing into another lane to complete the turn, you should keep the rear of your vehicle close to the curb. Leaving space to the right of your vehicle while turning right may indicate to other drivers that you are turning left, so they may attempt to pass you on your right.

If you must drive in reverse, you should first walk around the vehicle to check for hazards in your path of travel. Make frequent use of the mirrors on both sides of your vehicle while backing. Always back up as slowly as possible.