Handling Emergencies

Study questions with answers

8 sample Handling Emergencies questions with the correct answer, a short explanation, and the official handbook reference. Read through them, then take the quiz above.

1. 1. What does an antilock braking system do during hard braking?

   Correct answer: It keeps the wheels from locking so you can steer and stay in control

   ABS senses impending lockup and eases pressure to keep the wheels turning; it may not stop you sooner, but it lets you steer around obstacles and avoid skids.

   Source: Connecticut CDL Manual, Section 5.4.2 (Braking with Antilock Brakes)

2. 2. If the low air pressure warning comes on while you are driving, what should you do?

   Correct answer: Stop and safely park the vehicle as soon as possible

   A low-air warning may mean a leak; controlled braking only works while air remains, so stop and park safely right away before the spring brakes engage on their own.

   Source: Connecticut CDL Manual, Section 5.4.7 (Low Air Pressure)

3. 3. When may you fully apply the brakes in an emergency stop?

   Correct answer: When you routinely drive a straight truck or a combination that has working ABS on all its axles

   The one exception to braking as usual is that a vehicle with functioning ABS on all axles can be brought to an emergency stop with the brakes fully applied.

   Source: Connecticut CDL Manual, Section 5.4.2 (Braking with Antilock Brakes)

4. 4. How is stab braking performed?

   Correct answer: Fully apply the brakes, release when the wheels lock, then reapply once they roll again

   Stab braking presses the brakes all the way, releases when wheels lock, and reapplies fully once they start rolling; it can take up to a second for wheels to roll again after releasing.

   Source: Connecticut CDL Manual, Section 5.4.3 (Emergency Stops)

5. 5. Which two braking methods are recommended for an emergency stop?

   Correct answer: Controlled braking and stab braking

   In an emergency you can use controlled braking or stab braking; both aim to keep the vehicle straight while allowing you to steer if needed.

   Source: Connecticut CDL Manual, Section 5.4.3 (Emergency Stops)

6. 6. What describes the controlled braking method?

   Correct answer: Braking as hard as possible without locking the wheels, keeping steering movements small

   Controlled braking means applying maximum pressure short of locking the wheels; if you must steer more or the wheels lock, release and reapply as soon as you can.

   Source: Connecticut CDL Manual, Section 5.4.3 (Emergency Stops)

7. 7. As overheated brake drums expand, what happens to braking performance?

   Correct answer: The shoes must travel farther to reach the drum, and contact force drops

   Heat expands the drums so the shoes and linings have to move farther to touch them, and the force of that contact is weaker, so braking suffers.

   Source: Connecticut CDL Manual, Section 5.4.5 (Brake Fading or Failure)

8. 8. What most commonly causes brakes to fade?

   Correct answer: Excessive heat from overusing the brakes instead of relying on engine braking

   Using the service brakes too much overheats them; that heat changes the lining chemically and expands the drums, reducing braking force, which is brake fade.

   Source: Connecticut CDL Manual, Section 5.4.5 (Brake Fading or Failure)