DGT Weather & Hazardous Conditions 2 — Questions and Answers
Question 1: When driving in heavy fog, which lighting configuration is correct?
- High beams only
- Low beams and rear fog lights (Correct answer)
- Hazard lights and high beams
- No lights needed in daylight fog
Correct answer: Low beams and rear fog lights
Low beams reduce glare from fog particles, and rear fog lights help following drivers see you.
Question 2: What is 'black ice' and why is it especially dangerous?
- Dark-colored asphalt that absorbs heat
- A thin transparent layer of ice nearly invisible to drivers (Correct answer)
- Ice that forms only on bridges
- Compacted snow that turns dark from tire traffic
Correct answer: A thin transparent layer of ice nearly invisible to drivers
Black ice is a thin, transparent ice layer that blends with the road surface, giving drivers no visual warning.
Question 3: When driving in a dust storm with near-zero visibility, what should you do?
- Pull completely off the road, turn off all lights, and stay in the vehicle (Correct answer)
- Continue at reduced speed with hazard lights on
- Stop on the shoulder with hazard lights on
- Follow other vehicles' taillights closely
Correct answer: Pull completely off the road, turn off all lights, and stay in the vehicle
Pulling completely off the road prevents other drivers from following your lights into the storm and rear-ending you.
Question 4: How does rain affect a vehicle's braking distance on a highway?
- It reduces braking distance by cooling the brakes
- It has no significant effect at highway speeds
- It can double or more the normal dry braking distance (Correct answer)
- It only affects braking on curves, not straight roads
Correct answer: It can double or more the normal dry braking distance
Wet roads significantly reduce tire-to-road friction, greatly increasing the distance needed to stop.
Question 5: You notice your vehicle's windshield fogging up from the inside during rain. What is the most effective solution?
- Turn on the rear defroster only
- Use the air conditioning or defrost setting with outside air intake (Correct answer)
- Open all windows fully
- Increase cabin heat to maximum with recirculation on
Correct answer: Use the air conditioning or defrost setting with outside air intake
The A/C dehumidifies the air, and using outside air prevents moisture buildup inside the cabin.
Question 6: When should you turn on your vehicle's headlights in addition to nighttime hours?
- Only when visibility drops below 1,000 feet
- Whenever weather reduces visibility, such as rain, fog, or snow (Correct answer)
- Only in tunnels and at night
- Headlights are only required between dusk and dawn
Correct answer: Whenever weather reduces visibility, such as rain, fog, or snow
Most state laws require headlights whenever weather conditions reduce visibility, not only after dark.
Question 7: Which road surface is most likely to freeze first during cold weather?
- A flat rural highway
- A bridge or overpass (Correct answer)
- A multi-lane urban freeway
- A freshly paved road
Correct answer: A bridge or overpass
Bridges and overpasses are exposed to cold air on all sides and lose heat faster than roads built on ground.
DGT Weather & Hazardous Conditions 2
When driving in heavy fog, which lighting configuration is correct?