Road Signs

Study questions with answers

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

1. 1. If a sign reads 'Maximum Safe Speed' on a downgrade, what must you do?

   Correct answer: Never exceed the posted speed

   Never exceed the speed shown on a posted 'Maximum Safe Speed' or speed-limit sign on a downgrade, and heed signs about the grade's length and steepness.

   Source: North Carolina CDL Driver Handbook — Section 2: Driving Safely (2.6.6)

2. 2. A four-digit identification number preceded by 'UN' or 'NA' on a placard or orange panel identifies what?

   Correct answer: The specific hazardous material being carried

   The four-digit identification number, preceded by NA or UN, identifies the hazardous material so first responders can look it up in the Emergency Response Guidebook.

   Source: North Carolina CDL Driver Handbook — Section 2: Driving Safely (2.23.3)

3. 3. What shape and minimum size must a hazardous-materials placard be?

   Correct answer: A diamond shape at least 10 3/4 inches square

   Each placard has to measure a minimum of 10 3/4 inches on a side, sit as a diamond balanced on one point, and stay legible from every direction.

   Source: North Carolina CDL Driver Handbook — Section 2: Driving Safely (2.23.3)

4. 4. After going under an overpass during the road test, what might the examiner ask you?

   Correct answer: What the posted clearance or height was

   The examiner may ask what the posted clearance or height under the overpass was, so you should note traffic signs as you drive the route.

   Source: North Carolina CDL Driver Handbook — Section 13: On-road Driving (13.1.9)

5. 5. How many identical placards must a placarded hazardous-materials vehicle display?

   Correct answer: Four

   A placarded vehicle must show at least four identical placards, mounted on the front, the rear, and both sides.

   Source: North Carolina CDL Driver Handbook — Section 2: Driving Safely (2.23.3)

6. 6. Which hazard class covers corrosives such as battery acid?

   Correct answer: Class 8

   Hazard Class 8 covers corrosives, including hydrochloric acid and battery acid.

   Source: North Carolina CDL Driver Handbook — Section 2: Driving Safely (2.23.3)

7. 7. What does the round, black-on-yellow advance warning sign before a railroad crossing tell you to do?

   Correct answer: Slow down, look and listen, and be ready to stop

   This round yellow sign warns you ahead of the crossing to reduce speed, watch and listen for a train, and be ready to halt at the tracks if one approaches.

   Source: North Carolina CDL Driver Handbook — Section 2: Driving Safely (2.15.2)

8. 8. Which hazard class number is used for explosives?

   Correct answer: Class 1

   Hazard Class 1 is explosives, such as ammunition, dynamite, and fireworks.

   Source: North Carolina CDL Driver Handbook — Section 2: Driving Safely (2.23.3)