According to Japanese traffic law, when is headlight use mandatory?

Headlight use is mandatory on U.S. military installations according to Japanese traffic law. This regulation is in place to enhance safety and visibility, particularly in areas with increased foot traffic or where personnel may be present at all times, regardless of visibility conditions. Military installations prioritize the welfare of both military personnel and civilians, making clear guidelines regarding vehicle operation essential.

In contrast, the other options present scenarios that do not align with the specific laws governing vehicle operation on these installations. Using headlights only at nighttime does not account for situations where visibility might be impaired during the day due to weather conditions. Similarly, headlight use mandated solely during rush hours or clear weather does not adequately address the continuous nature of safety on military bases, which is why the policy specifically highlights use on installations regardless of the time of day or weather conditions.