general knowledge cdl b

What are the different types of retarders used in commercial vehicles?

Hydraulic

Electric

Engine brake or jake brake

Exhaust brake

What is the purpose of a retarder?

To help slow down a vehicle, reduce brake wear, and prevent service brakes from overheating, especially on long downhill grades.

Which is NOT a type of retarder: hydraulic, robotic, or electric?

Robotic

High beams should be used:

When it’s legal and safe to do so

What requires a special permit

Over weight and over size loads

What is defensive driving?

Watching for potential hazards, anticipating dangers, and preparing to avoid accidents.

What is the goal of defensive driving?

To prevent accidents and keep yourself and others safe.

What does emergency braking mean

Responding to an unexpected hazard by slowing down or stopping the vehicle.

What should you avoid when braking in an emergency?

Slamming on the brakes and locking the wheels. Maintain control of the vehicle.

What is snub braking

Apply the brakes firmly enough to slow down.

Reduce your speed to about 5 MPH below your safe speed.

Release the brakes.

Allow the vehicle to speed back up to your safe speed.

Repeat the process.

What is the proper way to use the brake pedal on a steep downhill grade?

Use snub braking. Slow 5 MPH below your safe speed, release the brakes, and repeat when you reach your safe speed.

What is snub braking?

Firmly applying and releasing the brakes to control speed on a steep downhill grade.

What are the two types of jackknifing?

Tractor jackknife and trailer jackknife.

What is a tractor jackknife?

The tractor skids sideways, usually because its drive wheels lose traction.

What is a trailer jackknife?

The trailer swings out to the side, forming an angle with the tractor.

What can cause a commercial vehicle's height to change?

The vehicle's weight and load can change its height.

Should you always assume posted overhead clearance signs are correct?

No. Check your vehicle's actual height and allow extra clearance.