Road Signs

Study questions with answers

12 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. A four-digit identification number shown on an orange panel on a tank vehicle is used mainly for what purpose?

   Correct answer: To let first responders identify the hazardous material

   The four-digit code lets emergency responders quickly identify the material being hauled by looking it up in the Emergency Response Guidebook.

   Source: New Jersey CDL Manual — Section 2: Driving Safely (Lists of Regulated Products)

2. 2. A roadside sign reading 'Maximum Safe Speed' before a long downgrade tells a commercial driver what?

   Correct answer: You must never go faster than the speed shown

   Where a maximum-safe-speed figure is posted for a grade, the driver must never travel faster than the number shown on that sign.

   Source: New Jersey CDL Manual — Section 2: Driving Safely (Speed on Downgrades)

3. 3. What color are the clearance and identification lights that must face forward at the front of a commercial vehicle?

   Correct answer: Amber

   During the walk-around, front-facing marker, clearance, and identification lights and reflectors must be clean, working, and amber in color.

   Source: New Jersey CDL Manual — Section 2: Driving Safely (Do Walk-around Inspection)

4. 4. What is the standard shape and orientation of a hazardous-materials placard on a commercial vehicle?

   Correct answer: A square sign turned on point to form a diamond

   Placards are square signs at least 250 mm on each side, set upright and balanced on one point so they read as a diamond from every direction.

   Source: New Jersey CDL Manual — Section 2: Driving Safely (Lists of Regulated Products)

5. 5. A round black-on-yellow advance warning sign appears before a passive railroad crossing. What kind of crossing is 'passive'?

   Correct answer: One with no traffic control device, leaving the decision to you

   A passive crossing has no active control device, so the driver alone must spot the crossing, look for a train, and judge whether it is clear to cross.

   Source: New Jersey CDL Manual — Section 2: Driving Safely (Types of Crossings)

6. 6. How many placards must a placarded hazardous-materials vehicle display, and where?

   Correct answer: Four identical placards on the front, rear, and both sides

   A placarded load must show four matching placards — one on the front, one on the rear, and one on each side — readable from all four sides.

   Source: New Jersey CDL Manual — Section 2: Driving Safely (Lists of Regulated Products)

7. 7. On a diamond-shaped hazard label or placard, what does the class number in the bottom corner indicate?

   Correct answer: The kind of hazard the cargo presents

   The number identifies the hazard class of the cargo — for example, class 3 for flammable liquids or class 8 for corrosives — so responders can gauge the danger.

   Source: New Jersey CDL Manual — Section 2: Driving Safely (Lists of Regulated Products)

8. 8. A red triangle bordered with an orange center displayed on the rear of a vehicle warns you that the vehicle is what?

   Correct answer: Unable to travel at normal traffic speed

   The red-and-orange triangular emblem marks a slow-moving vehicle, such as farm or construction equipment, that cannot keep up with normal traffic speeds.

   Source: New Jersey CDL Manual — Section 2: Driving Safely (Drivers Who Are Hazards)

9. 9. What does a crossbuck sign at a highway-rail grade crossing legally require of you?

   Correct answer: Yield the right-of-way to an approaching train

   The crossbuck marks the crossing itself and obligates the driver to give the right-of-way to any train that is approaching.

   Source: New Jersey CDL Manual — Section 2: Driving Safely (Warning Signs and Devices)

10. 10. Approaching a work zone marked with warning signs, a commercial driver should expect which of the following?

    Correct answer: Narrow lanes, sharp turns, and uneven road surfaces

    Work zones often bring narrowed lanes, tight curves, uneven surfaces, and distracted drivers, so a CDL holder should slow down and move through carefully.

    Source: New Jersey CDL Manual — Section 2: Driving Safely (Hazardous Roads)

11. 11. A round warning sign showing a black symbol on a yellow field placed some distance before a rail crossing is telling a commercial driver to do what?

    Correct answer: Ease off the throttle, watch and listen for a train, then halt at the rails if one is nearing

    The advance warning sign for a grade crossing means ease off the accelerator, watch and listen for a train, and be set to halt at the rails if one is coming.

    Source: New Jersey CDL Manual — Section 2: Driving Safely (Railroad-highway Crossings)

12. 12. Pavement painted with a large 'X', the letters 'RR', and a no-passing line carries what meaning?

    Correct answer: A railroad crossing is coming up, the same as the advance warning sign

    Those road markings deliver the same message as the round advance warning sign — a railroad crossing lies ahead.

    Source: New Jersey CDL Manual — Section 2: Driving Safely (Warning Signs and Devices)