Ask a trooper: Fog lights must not be too bright or aimed too high
Q: I notice a lot of people have fog lights on when I meet them on the road in the evening or at night; some are very bright and make seeing the road very difficult, and some appear to be out of alignment and are blinding. Can you address this is...
Q: I notice a lot of people have fog lights on when I meet them on the road in the evening or at night; some are very bright and make seeing the road very difficult, and some appear to be out of alignment and are blinding. Can you address this issue?
A: There are specific requirements for fog lights, and if they are aimed too high and/or are too bright they are not legal for just that reason - even if they are in compliance with the rest of the law. All lights for vehicles have to be approved by the Commissioner of Public Safety and they have to be allowed (or required) by statute.
Minnesota State Statute 169.56 Sub 2 says, "Any motor vehicle may be equipped with not to exceed two fog lamps mounted on the front at a height not less than 12 inches nor more than 30 inches above the level surface upon which the vehicle stands and so aimed that when the vehicle is not loaded none of the high-intensity portion of the light to the left of the center of the vehicle shall at a distance of 25 feet ahead project higher than a level of 4 inches below the level of the center of the lamp from which it comes. Lighted fog lamps meeting the above requirements may be used with lower headlamp beams."
Another relevant law is M.S.S. 169.63(b), which also tells us that, "When a motor vehicle equipped with headlamps, as (herein) required, is also equipped with any auxiliary lamps, spot lamps or any other lamps on the front thereof projecting a beam of intensity greater than 300-candle power, not more than a total of four of any such lamps on the front of a vehicle shall be lighted at any one time when upon a highway."
Some of the lights you are seeing might actually be "daytime running lights." Many of those are on automatically and are installed by the manufacturer. The driver may not always have the ability to turn them off. They cannot be used in lieu of headlights, but sometimes they are, which would be a violation. It is best practice to keep your lights on at all times to make yourself more visible to other drivers. It's the law to have headlights (and taillights) on during rain. I hope some of this information helps.
Sgt. Neil Dickenson is a public information officer with the Minnesota State Patrol.