Signals & Pavement Markings

Study questions with answers

7 sample Signals & Pavement Markings questions with the correct answer, a short explanation, and the official handbook reference. Read through them, then take the quiz above.

1. 1. What is the 'wig wag' found on some air-brake vehicles?

   Correct answer: A mechanical arm that drops into view when pressure is low

   The wig wag is a mechanical arm that swings into the driver's view when system pressure falls below 55 psi.

   Source: 5.1.11 Low Air Pressure Warning

2. 2. On large buses, the low-pressure warning devices commonly activate at about what pressure?

   Correct answer: 80 to 85 psi

   For big buses, these warning devices commonly trip much earlier, around 80 to 85 psi.

   Source: 5.1.11 Low Air Pressure Warning

3. 3. The visible low-air warning must switch on before tank pressure drops below what level?

   Correct answer: 55 psi

   A required warning you can see must activate before the air pressure falls under 55 psi.

   Source: 5.1.11 Low Air Pressure Warning

4. 4. On the application pressure gauge, needing more and more pressure to hold a steady speed points to what?

   Correct answer: The brakes fading

   If you must keep raising application pressure to maintain speed, it signals fading brakes, and you should slow down and gear down.

   Source: 5.1.10 Application Pressure Gauge

5. 5. What does a supply pressure gauge tell the driver?

   Correct answer: How much air is stored in the tanks

   The supply pressure gauge, connected to the air tank, shows how much pressure is stored in the system.

   Source: 5.1.9 Supply Pressure Gauges

6. 6. What color is the malfunction lamp that warns of an ABS problem?

   Correct answer: Yellow

   Vehicles with ABS use yellow malfunction lamps to alert the driver that something in the antilock system isn't working.

   Source: 5.1.16 Antilock Braking Systems (ABS)

7. 7. How does an air-brake system turn on the brake lights for drivers behind you?

   Correct answer: Through an electric switch triggered by air pressure

   An air-pressure-operated electric switch turns on the stop lights whenever the air brakes are applied.

   Source: 5.1.12 Stop Light Switch