Fog and Reduced Visibility - ONLINE CDL SCHOOL

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Fog and Reduced Visibility

Build confidence with 10 original questions about Fog and Reduced Visibility. Review your answers and explanations after finishing.

Supplemental study practice. This is not a government licensing exam or ELDT certification, and does not replace hands-on training. Follow your state’s current handbook.

1 / 10

What is the safest action to take if you encounter heavy fog while driving a commercial vehicle?

Pull off the road at a rest area or truck stop until visibility improves

Stop on the shoulder and wait with your lights off

Turn on your high-beam headlights and continue driving

Speed up to get through the fog quickly

2 / 10

When driving in fog during the day, which lights should you use for best visibility?

No lights, to avoid glare

High-beam headlights only

Parking lights only

Low-beam headlights and fog lights

3 / 10

Why should you avoid stopping along the side of the road in fog unless absolutely necessary?

Stopping will cause your windows to fog up

Other drivers may not see your vehicle and could hit you

It is illegal to stop in fog

Your engine may stall in foggy conditions

4 / 10

What is the recommended action if you feel sleepy while driving a commercial vehicle?

Drink coffee and keep driving

Open the window for fresh air

Turn up the radio to stay awake

Stop at the nearest safe place and sleep

5 / 10

What should you do before you enter foggy conditions on the highway?

Turn off all lights

Open your windows

Slow down

Speed up to get through quickly

6 / 10

When driving in fog, why should you use roadside highway reflectors as guides?

They help you determine how the road may curve ahead

They indicate the speed limit

They warn you of upcoming stop signs

They show where other vehicles are parked

7 / 10

Why should you avoid passing other vehicles when driving in fog?

Visibility is limited and it is harder to see oncoming traffic

Passing is always illegal in fog

It increases tire wear

Your headlights will blind other drivers

8 / 10

What is a recommended way to help other drivers notice your vehicle when driving in fog?

Honk your horn repeatedly

Turn on your 4-way flashers

Drive with your hazard lights off

Use only your parking lights

9 / 10

What is the minimum tread depth required for front tires on a commercial vehicle in winter conditions?

1/32 inch in every major groove

2/32 inch in every major groove

6/32 inch in every major groove

4/32 inch in every major groove

10 / 10

If you cannot see well enough while driving in winter weather, such as if your wipers fail, what should you do?

Stop safely and fix the problem

Turn on your high beams

Open your windows for better visibility

Continue driving slowly

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