Ch. 6 · Hazardous Areas

In dense fog on an expressway when visibility is less than 100 meters, you must turn on your headlights, clearance lights, tail lights, and other lights while driving.

[True / False · Medium]

Answer: ✓ True

Explanation

The Rules of the Road set the threshold for turning on headlights and other lights in tunnels or dense fog at 50 meters of visibility on regular roads and 200 meters on expressways. On an expressway where you cannot see 100 meters ahead, you naturally cannot see 200 meters either, so this meets the threshold and the lights are required.

Driving school curriculumStage 2 – Topic 7: Driving in adverse conditions

Hikari
Hikari
Didn't the last question say 50 meters? Now it's 100 on an expressway—feels contradictory!
Misaki
Misaki
Good catch, but this one is true. On expressways, the threshold is actually 200 meters, so if you can't see 100 meters, you definitely can't see 200 either—lights are required.
Hikari
Hikari
Ohh, so expressways have a stricter distance because of higher speeds?
Misaki
Misaki
Exactly. Just remember: 50 meters for regular roads, 200 for expressways—and 100 on an expressway always triggers the rule.

Source: Ch. 6 Hazardous Areas · Section (第3節 夜間 - 灯火) · Rules of the Road, Ch.6 §3 (Night) / 2 Lights (1) — Even in daytime, turn on your headlights, side lights, and tail lights when you cannot see 50 m ahead (200 m on expressways), e.g. in tunnels or thick fog.

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Source content excerpted from the NPA “Rules of the Road” instructional manual, in the public domain under Japanese Copyright Act Article 13(2). Explanations are AI-assisted and copyrighted by the MenkyoQuest editorial team.