California · Driving practice
When Driving Into Fog You Should Use Low Beams
More light is not automatically more useful visibility. In the original California question, low beams are the correct choice when you must drive in heavy fog or smoke. High beams can reflect back and create glare instead of making the path clearer. Read that wording carefully: selecting low beams does not establish that continuing is safe in every density of fog. The question tests the light choice, while the actual driving decision still depends on the conditions. The explanation concerns reflected light and usable visibility. Source
The short answer
Use low-beam headlights if you must drive in heavy fog or smoke, rather than high beams.
Read the source
Check your understanding
Choose an answer, or open “Show answer” to read the explanation. This practice does not change your saved tests or mistakes.
Study tools & help
Loading tools…
Why this answer fits the situation
A brighter-looking beam that returns glare to the driver is not helping reveal the road ahead. Low beams address that specific problem; they do not remove the need for a controlled speed, observation and space. The California handbook treats severe visibility separately from merely choosing a lamp setting. Do not infer a universal safe speed or distance from this short headlight question.
How to read the decision on the road
Identify what the question asks before selecting a broad safety statement. Here it asks which headlights, not whether the trip must continue or how fast to travel. Then compare the alternatives by whether they help illuminate the path without the high-beam glare described in the original explanation. If conditions no longer permit safe progress, a different decision is needed; the low-beam answer is not a promise that every foggy route is drivable.
Why the other choices do not fit
High beams
High beams can reflect from fog and create glare. Choosing them simply because the road is hard to see mistakes extra brightness for better usable sight. The original explanation identifies that specific reason for preferring low beams.
Parking lights only
Parking lights alone do not answer the stated need for headlights while driving in heavy fog or smoke. This option substitutes a different kind of light rather than making the low-versus-high choice addressed by the handbook guidance.
No lights during daytime
Daytime does not make the visibility problem disappear. The prompt describes heavy fog or smoke, not ordinary clear daylight. Removing the lights because of the time of day ignores the condition that the question asks you to respond to.