Missouri CDL — General Knowledge: Road Signs Practice Test

Question 1

What does the crossbuck sign found at a railroad grade crossing require you to do?

Accepted Answer

Give the approaching train the right-of-way — The crossbuck marks the crossing itself and legally obligates a driver to give the right-of-way to any train using the tracks.

Answer

Come to a complete stop every time regardless of traffic

Answer

Sound your horn twice before crossing

Answer

Cross only when a flagman waves you through

Question 2

A hazardous materials placard is displayed in what shape?

Accepted Answer

A diamond, standing on a point — Placards warning of hazardous cargo are square-shaped signs stood on one point so they form a diamond.

Answer

A rectangle laid on its long side

Answer

A circle

Answer

An octagon like a stop sign

Question 3

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

Accepted Answer

Class 8, Corrosives — Corrosive substances like battery fluid and hydrochloric acid are grouped under hazard class 8.

Answer

Class 6, Poisons

Answer

Class 4, Flammable Solids

Answer

Class 2, Gases

Question 4

The round, yellow railroad advance warning sign posted before a crossing is telling a commercial driver to do what?

Accepted Answer

Slow down, look and listen for a train, and be prepared to stop — The advance warning sign appears ahead of a public crossing so you can ease off the throttle, watch and listen for a train, and be ready to halt at the tracks if one is coming.

Answer

Speed up so you clear the tracks before any train arrives

Answer

Ignore the sign because a gate will always warn you

Answer

Stop only if you are hauling passengers

Question 5

The slow-moving vehicle emblem you may see on farm machinery or tractors looks like what?

Accepted Answer

A red triangle with an orange center — Vehicles that travel below normal speed often display a warning symbol shaped like a triangle, red around the edges with an orange middle.

Answer

A blue circle with a white border

Answer

A solid green square

Answer

A yellow diamond with black lettering

Question 6

When a downgrade posts a sign reading “Maximum Safe Speed,” what should a truck driver do?

Accepted Answer

Never exceed the speed shown — A posted maximum safe speed on a grade sets a ceiling you must never go above, and you should also watch for signs describing how long and steep the hill is.

Answer

Treat it as a suggestion for cars only

Answer

Add ten miles per hour because trucks brake better

Answer

Match the speed of the car ahead instead

Question 7

At a crossing with more than one set of tracks, how are you told how many tracks you must cross?

Accepted Answer

By a sign placed below the crossbuck — When a road spans multiple sets of rails, a small sign mounted beneath the crossbuck states the number of tracks present.

Answer

By counting the flashing lights on the mast

Answer

By the color of the pavement paint

Answer

The number is never posted anywhere

Question 8

Signs marking a runaway-vehicle escape ramp on a mountain grade exist mainly to do what?

Accepted Answer

Show where a runaway truck can be stopped safely — Escape ramps are engineered to bring runaway trucks to a safe halt, and signs alert drivers to where those ramps are located along the route.

Answer

Point out a rest area for meals

Answer

Advertise a nearby weigh station

Answer

Mark the state line

Question 9

Painted pavement markings at a two-lane railroad crossing generally consist of what?

Accepted Answer

An X with the letters RR plus a no-passing marking — The paint at such a crossing shows a large “X” with the letters “RR,” and on two-lane roads it is paired with a no-passing marking.

Answer

A single dashed yellow line only

Answer

A row of green arrows

Answer

The word STOP spelled out three times

Question 10

Ammunition, dynamite, and fireworks fall under which hazard class?

Accepted Answer

Class 1, Explosives — Items such as ammunition, dynamite, and fireworks are given as examples of the explosives class, class 1.

Answer

Class 2, Gases

Answer

Class 5, Oxidizers

Answer

Class 9, Miscellaneous

Question 11

How many identical placards must a placarded hazardous-materials load display on the vehicle?

Accepted Answer

Four, on the front, rear, and both sides — A load that must be placarded carries four matching placards, one on each side plus the front and the back.

Answer

Only one, on the rear

Answer

Two, on the left and right

Answer

Three, skipping the front

Question 12

In the hazard class table, which class covers gasoline and acetone?

Accepted Answer

Class 3, Flammable — Gasoline and acetone are listed as examples under the flammable class, hazard class 3.

Answer

Class 1, Explosives

Answer

Class 7, Radioactive

Answer

Class 8, Corrosives

Road Signs

Study questions with answers

1. What does the crossbuck sign found at a railroad grade crossing require you to do?

2. A hazardous materials placard is displayed in what shape?

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

4. The round, yellow railroad advance warning sign posted before a crossing is telling a commercial driver to do what?

5. The slow-moving vehicle emblem you may see on farm machinery or tractors looks like what?

6. When a downgrade posts a sign reading “Maximum Safe Speed,” what should a truck driver do?

7. At a crossing with more than one set of tracks, how are you told how many tracks you must cross?

8. Signs marking a runaway-vehicle escape ramp on a mountain grade exist mainly to do what?

9. Painted pavement markings at a two-lane railroad crossing generally consist of what?

10. Ammunition, dynamite, and fireworks fall under which hazard class?

11. How many identical placards must a placarded hazardous-materials load display on the vehicle?

12. In the hazard class table, which class covers gasoline and acetone?

More CDL — General Knowledge topics

Practice Road Signs in another state