Question: I enjoy reading your column in the weekly newspaper. I have a question I hope you can address.
We’ve had some heavy fog recently and I get frustrated with the vehicles that do not have their lights on. Sometimes the headlights are on and the rear lights are not.
What is the advice/law in using your lights during the daytime when there is fog, rain or snow?
Answer: Thank you for the question and you bring up a lot of good advice and points. Your headlights and taillights must be turned on at sunset and used until sunrise. Use them during weather conditions that include rain, snow, hail, sleet or fog and any time you cannot clearly see the road ahead for at least 500 feet.
People often fail to turn on their headlights in rain and fog due to a false sense of security, over-reliance on automatic light sensors that don’t always activate, and the mistaken belief that lights are only for seeing, rather than being seen. Other factors include confusion with daytime running lights, or DRL, and simply forgetting.
Key reasons for this dangerous habit include:
• Misunderstanding of purpose: Many drivers do not realize that in the rain, headlights are crucial to make their vehicle visible to others, especially from the rear.
• Automatic system failure: Auto-light sensors often do not register daytime, overcast or rainy conditions as “dark enough” to activate headlights.
• Dashboard/DRL confusion: Modern dashboards are often always lit, leading drivers to mistakenly believe their headlights are on.
• Habit/forgetfulness: Drivers often forget to manually activate lights if they are used to automatic systems.
• Ineffective DRLs: While daytime running lights are on, they often do not activate rear tail lights, making the car invisible from behind.
I think in the newer vehicles, the owners don’t check if the lights are on thinking they automatically come on under those conditions. More often than not my 2025 Subaru does not have any lights on — at least in the early stages of lower-vision conditions. I look at my dashboard and can see if the headlights are on via the instrument lights. Then I go outside to the rear and sometimes the rear lights are not on.
The best way I have found is to get to know your vehicle switches and lights. So, when I am parked, I can try the different positions on the switch to see exactly what lights are coming on. If the light conditions haven’t triggered the auto lights, I can manually turn them on. In general, I keep the switch in the position of headlights and running lights (rear lights included) automatically coming on when light conditions warrant coming on. They automatically turn off when the car is turned off.
Any questions concerning traffic related laws or issues in Minnesota, send your questions to Trooper Troy Christianson, Minnesota State Patrol, 2900 48th St., NW, Rochester MN 55901-5848; or send an email to: Troy.Christianson@state.mn.us.