Wisconsin CDL — General Knowledge practice
Wisconsin CDL — General Knowledge: Road Signs practice test
Learn the shapes, colors, and meanings of regulatory, warning, and guide signs — from stop and yield to construction and school-zone signs.
Content reviewed against official driver handbooks · August 12, 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.
Show all 12 questions with answers
1. 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
2. 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
3. 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?
4. 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?
5. 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
6. 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
7. 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
8. 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
9. 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
10. 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
11. 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?
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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