First Amendment Right to Flash Headlights Warning of Speed Trap

Published On: 6th February 2014

A Missouri federal district court judge has ruled that drivers a have a First Amendment right to warn others of police presence by flashing vehicle headlights. The civil rights suit by Michael Elli was initiated after he was arrested for flashing his headlights at other drivers warning of a radar speed trap by police in Ellisville, MO. In response to city’s claim that Michael Elli was interfering with a police investigation by flashing his headlights, U.S. District Judge Henry Autrey stated that flashing headlights to oncoming motorists, “sends a message to bring one’s driving in conformity with the law — whether it be by slowing down, turning on one’s own headlamps at dusk or in the rain, or proceeding with caution.” Read more on the ruling here..

Although Minnesota courts have not dealt with the First Amendment issue as it relates to flashing headlights, the MN Court of Appeals has held that a driver flashing high-beams at oncoming traffic is not a basis for traffic stop when there is no indication the headlights projected “glaring rays…into the eyes of the oncoming driver.” In Sarber v. Commissioner of Public Safety, the driver was stopped and arrested for DWI after he flashed his high-beams at a Mille Lacs County deputy. Because Minnesota law only prohibits the “use of headlights in a manner that blinds or impairs other drivers,” and there was no evidence of the headlights blinded the deputy, the Court reversed Sarber’s driver’s license revocation and plate impoundment.


Coley Grostyan is a Minnesota DWI and traffic defense attorney who regularly represents clients accused of traffic violations.

Law Office of Coley J. Grostyan, PLLC
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Minneapolis, MN 55415
First Amendment Right to Flash Headlights Warning of Speed Trap