Ask a trooper: Rules for high-beam headlights

Q: What are the rules for using high-beam lights? When on a divided highway like Interstate 35, must I turn off high-beam lights for approaching cars? What is the distance where I am required to turn them off, and is this the same for oncoming traffic and when following traffic?

A: Yes, technically drivers must turn off high beam lights for approaching cars on I-35. The law makes no distinction about being on a two-lane, four-lane or other multi-laned highway when it comes to the headlight dimming requirements. You must dim before oncoming traffic is within 1,000 feet and before coming up behind traffic within 200 feet.

Q: In rain, fog, snow, darkness, when must headlights be on?

A: According to M.S.S. 169.48, all required lighting, not just headlights, has to be on at any time from sunset to sunrise; at any time when it is raining, snowing, sleeting or hailing; and at any other time when visibility is impaired by weather, smoke, fog or other conditions when there is not sufficient light to render clearly discernible persons and vehicles on the highway at a distance of 500 feet ahead.

Q: Are parking lights OK during daytime rain?

A: No. During rain, all vehicle lights must be on.

Q: An observation: Running lights are on only for the front of the vehicle and not the rear. I have noticed this on occasion, and I think running lights give people a false sense of security that the rear of the vehicle is lit when it is not.

A: That is all true and correct.

Q: There are aftermarket headlamps that are blue and seemingly brighter than standard headlamps. Are any headlamps prohibited by law?

A: Yes, there are aftermarket headlamps that are prohibited by law. Also, any lights that are too bright or blinding are prohibited, but there are exceptions (like some of the newer lights that appear to be blue — some are legal and some are not. Many of the aftermarket lights are not legal and probably all of the factory ones are legal).

Sgt. Curt S. Mowers is a public information officer with the Minnesota State Patrol.

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