When must a driver use their headlights according to Iowa law?

In Iowa, the law regarding the use of headlights is designed to enhance safety on the roads under various visibility conditions. The correct answer encompasses all the scenarios where headlights must be used.

Drivers are required to use their headlights during nighttime hours to ensure visibility for themselves and for other drivers. This is a common regulation aimed at preventing accidents that can occur in low light situations.

In addition to nighttime use, when weather conditions are poor—such as during rain, fog, snow, or other situations that impair visibility—headlights must also be activated. This practice helps increase the visibility of the vehicle to other road users and also allows the driver to see better.

Most importantly, the law specifies that whenever the windshield wipers are in operation, headlights must be turned on. This rule directly correlates the use of wipers, typically indicating that conditions are poor enough to hinder visibility, thereby necessitating the use of headlights.

Thus, headlights should be used in all of these situations as mandated by Iowa law, contributing to overall road safety.