Safe Driving Practices

Study questions with answers

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

1. 1. An air brake setup actually combines how many separate braking systems into one?

   Correct answer: Three - the service, parking, and emergency brakes

   The handbook explains that air brakes are really three systems working together: the service brake, the parking brake, and the emergency brake.

   Source: Section 5 - Air Brakes (introduction)

2. 2. On a long, steep downgrade, the service brakes should be treated as what?

   Correct answer: A supplement to the engine's braking effect

   The manual stresses that on a steep grade the brakes only add to the slowing effect of the engine held in a low gear.

   Source: 5.4.6 Proper Braking Technique

3. 3. Using the recommended snub-braking method downhill, about how long should each brake application last?

   Correct answer: Roughly three seconds

   You apply firmly to slow about 5 mph below your safe speed and then release; each of these applications should last roughly three seconds.

   Source: 5.4.6 Proper Braking Technique

4. 4. What do air brakes rely on to actually apply the brakes?

   Correct answer: Compressed air

   Air brakes use compressed air, rather than fluid, to press the shoes against the drums and stop a large, heavy vehicle.

   Source: Section 5 - Air Brakes (introduction)

5. 5. Why can brakes that are out of adjustment lead the other brakes to fade?

   Correct answer: They stop carrying their share, so the rest overheat

   Misadjusted brakes quit carrying their load first, which forces the properly adjusted brakes to overheat and fade.

   Source: 5.4.5 Brake Fading or Failure

6. 6. What most commonly causes air brakes to fade on a long descent?

   Correct answer: Excessive heat from overusing the service brakes

   Riding the service brakes builds up excessive heat, which changes the lining chemically and expands the drums, cutting braking force.

   Source: 5.4.5 Brake Fading or Failure

7. 7. What can happen to drum brakes if they absorb more heat than they can handle?

   Correct answer: They can quit working entirely

   Friction from the shoes creates heat, and too much of it can cause the brakes to quit working.

   Source: 5.1.8 Foundation Brakes

8. 8. When making a normal stop with a manual transmission, when should you press the clutch?

   Correct answer: Not until engine rpm has dropped near idle

   For a smooth normal stop you keep the clutch out until the engine is nearly at idle speed, then select a starting gear.

   Source: 5.4.1 Normal Stops