Basic Vehicle Control Flashcards

What should you do if your commercial vehicle's brakes begin to fade on a long downhill grade?

Answer: Downshift immediately and look for an escape ramp

Brake fade signals overheated brakes; downshifting increases engine braking and escape ramps provide a last resort to stop safely.

Which of the following best describes 'stab braking' for commercial vehicles without ABS?

Answer: Applying full brake pressure and releasing when wheels lock, then reapplying

Stab braking involves applying full pressure until wheels lock, releasing briefly to let them roll, then reapplying, repeating as needed.

When should you downshift a manual transmission commercial vehicle?

Answer: Before entering a curve or grade, not while in it

Downshift before curves and hills so you can focus on steering and speed control rather than shifting during the maneuver.

What is the correct procedure for turning around in a commercial vehicle when space is limited?

Answer: Drive around the block to avoid reversing

CDL training recommends going around the block rather than attempting a three-point turn, since reversing a large vehicle in tight areas is dangerous.

How does cargo weight affect the braking distance of a commercial vehicle?

Answer: Heavier loads increase braking distance because more inertia must be overcome

Greater vehicle mass requires more braking force and distance to stop because inertia increases with weight.

What is the purpose of a runaway truck ramp (escape ramp)?

Answer: To provide an emergency stopping area for vehicles with brake failure on steep grades

Escape ramps use deep gravel or an uphill grade to stop a truck that has lost braking ability on a steep downhill.

In a commercial vehicle with air brakes, what happens when you push the brake pedal down?

Answer: Air pressure is directed to the brake chambers to apply the brakes

Pressing the pedal opens valves that send compressed air to the brake chambers, which push brake shoes or pads against drums or rotors.