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Wisconsin CDL — General Knowledge practice

Road Signs

Learn the shapes, colors, and meanings of regulatory, warning, and guide signs — from stop and yield to construction and school-zone signs.

Questions reviewed against the official Wisconsin driver handbook · July 7, 2026

12 questions · pass with 10 correct. You get instant feedback and an explanation after every answer.

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. Dynamite, fireworks and ammunition are grouped in which hazard class?

    Correct answer: Class 1

    Those items are explosives, which the hazard-class list identifies as Class 1.

    Source: Wisconsin CDL Manual, Section 2.23.1 — What Are Hazardous Materials?

  2. 2. Battery fluid and hydrochloric acid are examples of which hazard class?

    Correct answer: Class 8

    Both eat away at materials on contact, so they are corrosives, listed as Class 8.

    Source: Wisconsin CDL Manual, Section 2.23.1 — What Are Hazardous Materials?

  3. 3. The advance warning sign posted ahead of a public rail crossing has what shape and color?

    Correct answer: A round yellow sign with black markings

    A round yellow sign with a black border and letters is posted before the tracks to prompt drivers to slow, look and listen.

    Source: Wisconsin CDL Manual, Section 2.15.2 — Warning Signs and Devices

  4. 4. A four-digit identification number on a placard or orange panel is preceded by which letters?

    Correct answer: UN or NA

    First-responder identification numbers are printed with the prefix UN or NA ahead of the four digits.

    Source: Wisconsin CDL Manual, Section 2.23.3 — Lists of Regulated Products

  5. 5. What is the required shape of a hazardous materials placard?

    Correct answer: A square turned to form a diamond

    Placards are squares set on a point so they read as a diamond, and they must be legible from every direction.

    Source: Wisconsin CDL Manual, Section 2.23.3 — Lists of Regulated Products

  6. 6. What does the reflective triangle emblem with an orange center and a red border tell you about a vehicle ahead?

    Correct answer: It moves much slower than surrounding traffic

    That badge is the slow-moving vehicle emblem, warning that the unit ahead travels well below normal traffic speed.

    Source: Wisconsin CDL Manual, Section 2.8.3 — Drivers Who Are Hazards

  7. 7. What is the minimum size for a hazardous materials placard?

    Correct answer: 9.8 inches per side

    Each placard must measure at least 9.8 inches, or 250 millimeters, on every side.

    Source: Wisconsin CDL Manual, Section 2.23.3 — Lists of Regulated Products

  8. 8. How many identical placards must appear on a vehicle that is required to display them?

    Correct answer: Four

    A placarded load must show four matching placards, one on the front, one on the rear and one on each side.

    Source: Wisconsin CDL Manual, Section 2.23.3 — Lists of Regulated Products

  9. 9. Gasoline falls under which hazard class shown on placards?

    Correct answer: Class 3

    Gasoline is a flammable liquid, placing it in hazard Class 3 on the hazard-class table.

    Source: Wisconsin CDL Manual, Section 2.23.1 — What Are Hazardous Materials?

  10. 10. At a crossbuck, what does a small sign mounted just below it tell you when it reads a number?

    Correct answer: The number of tracks to be crossed

    A number panel under the crossbuck states how many separate sets of tracks the crossing spans.

    Source: Wisconsin CDL Manual, Section 2.15.2 — Warning Signs and Devices

  11. 11. A crossbuck posted at a grade crossing carries what instruction for drivers?

    Correct answer: Yield the right of way to trains on the tracks

    The crossbuck marks the crossing and legally requires you to give the right of way to any approaching train.

    Source: Wisconsin CDL Manual, Section 2.15.2 — Warning Signs and Devices

  12. 12. Propane, helium and oxygen are placarded under which hazard class?

    Correct answer: Class 2

    These are compressed or liquefied gases, which the hazard table lists as Class 2.

    Source: Wisconsin CDL Manual, Section 2.23.1 — What Are Hazardous Materials?

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Every Wisconsin question is written from the official Wisconsin driver handbook and checked against its current edition. DMV Test Free is a free, independent study resource — not affiliated with any DMV or government agency. About DMV Test Free