Blog Post

Do You Have a Constitutional Right to Honk Your Car Horn?

April 17, 2023 | by Scott Bomboy

A lawsuit in California about the use of a car horn at a political protest is bringing back a contested question involving the tension between free speech and public safety concerns.

On April 7, 2023, the Ninth Circuit Court of Appeals (left) ruled in Porter v. Martinez that a San Diego County sheriff’s deputy had the power to cite a woman who honked her car horn 14 times at a 2017 rally protesting against Representative Darrell Issa. The panel divided 2-1 over the case.

The issue of excessive horn honking is not a new one. Similar incidents in the past have led to court decisions in several other states. But the California case may still have some gas in the tank in the legal appeals system, since the dissenting Ninth Circuit judge raised a serious constitutional question.

According to court records, Susan Porter attended a protest at Rep. Issa’s office in Vista, California. As she left the scene, Porter honked her car horn in support of the protesters in three bursts, totaling 14 honks. 

A San Diego County sheriff’s deputy, Kelly Martinez, pulled over Porter, and cited Porter under Section 27001 of the California Vehicle Code. The current code reads as follows: “[T]he driver of a motor vehicle when reasonably necessary to insure safe operation shall give audible warning with his horn. The horn shall not otherwise be used, except as a theft alarm system.”

When the deputy did not appear at a hearing, Porter’s citation was dropped. However, she then filed a civil suit. Porter argued that the threat of a similar fine stopped her from honking in support of other public demonstrations. 

Link: Watch The Ninth Circuit Hearing on YouTube

Her counsel from the First Amendment Coalition argued that application of the code violated Porter’s First Amendment and 14th Amendment rights to express not only her political views, but her ability to honk to “greet friends” or “celebrate weddings or victories.” The state of California countered that the law was content neutral and was intended to serve important public purposes like promoting public safety and lowering noise pollution. A district court agreed with the state of California, citing expert testimony from a California Highway Patrol officer.

On April 7, 2023, the U.S. Court of Appeals for the Ninth Circuit ruled on the First Amendment questions posed by Porter. It rejected Porter’s argument that Section 27001 targeted political speech, applied intermediate scrutiny, and concluded the law was narrowly drawn to advance a substantial governmental interest.

“Section 27001 does not single out for differential treatment, for example, political honking, ideological honking, celebratory honking, or honking to summon a carpool rider,” wrote Circuit Judge Michelle T. Friedland. “Instead, the law ‘applies evenhandedly to all who wish to’ use the horn when a safety hazard is not present. . . . Section 27001 draws a line based on the surrounding factual situation, not based on the content of expression.” The majority also cited the trooper’s testimony that indiscriminate horn honking can confuse drivers and pedestrians.

Circuit Judge Marsha S. Berzon disagreed, concluding that “honking in response to a political protest” is protected speech. Judge Berzon said other horn honkers at the protest were greeted with a positive crowd response. In the end, Berzon said the law conflicts with the First Amendment. “Section 27001 violates the First Amendment because Defendants have not shown that the statute furthers a significant government interest as applied to political protest honking, and because the statute is not narrowly tailored to exclude such honking.”

Other Cases About the Honking Question

A look at past cases in other jurisdictions about horn honking shows a pattern of mixed outcomes.

In 2011, the state Supreme Court of Washington ruled in State v. Immelt in favor of a woman who was arrested in a dispute with a neighbor. Helen Immelt’s neighbor complained that Immelt was raising chickens in violation of a homeowners’ association covenant, and Immelt honked a car horn for a 5-to-10 minute period at the neighbor’s house. 

Snohomish County charged Immelt with violating a public safety ordinance that barred horn honking “for a purpose other than public safety, or originating from an officially sanctioned parade or other public event.” The lower courts ruled in favor of the state, but the state Supreme Court concluded the law was overbroad. The law’s “exceptions for public safety and officially sanctioned parades or other public events cannot reasonably be construed to encompass myriad instances of protected expression that occur outside of public events,” wrote Justice Debra L. Stephens. However, the Washington state Supreme Court did not rule on the First Amendment question.

In a case from Montana in 1998, the state Supreme Court held that a woman could be charged under the state law with disorderly conduct for honking to protest a recreational vehicle park near the Yellowstone River. The court explained that the honking “clearly annoyed and harassed the [residents] and their guests at the RV Park and, on the face of it, could not have been intended otherwise.”

But an Oregon court ruled in 1992 that honking restrictions violated the state constitution’s free speech provisions. There, drivers were fined in Eugene, Oregon, for honking at an anti-war demonstration after they were asked by protesters to honk against the Persian Gulf War. The state court found that Oregon’s honking law was overbroad.

SCOTUS on Noise Ordinances

At the same time, a New York federal district court ruling in 1985 upheld a fine against a motorist who honked repeatedly in a Manhattan traffic jam as a protest against road conditions, citing a Supreme Court precedent in Kovacs v. Cooper (1949). “The ordinance is … reasonably related to two significant governmental interests, reducing noise and maximizing the utility of car horns,” said the U.S. District Court for the Southern District of New York.

In a 5-4 decision, the Supreme Court in Kovacs held that Trenton, N.J., could regulate trucks that played loud music on streets—or vehicles equipped with a public address system and loudspeakers—usually in order to project recorded messages. Justice Stanley Reed wrote that “we think it is a permissible exercise of legislative discretion to bar sound trucks with broadcasts of public interest, amplified to a loud and raucous volume, from the public ways of municipalities.”

Among the dissenters, Justice Hugo Black warned that laws like the one at issue in the case had the potential to provide government with the power to use noise regulations to chill free speech. “The basic premise of the First Amendment is that all present instruments of communication, as well as others that inventive genius may bring into being, shall be free from governmental censorship or prohibition. Laws which hamper the free use of some instruments of communication thereby favor competing channels,” Black wrote in his dissent.

What’s Next?

If Porter and her attorneys appeal, the Washington Post reported that the appellants have until April 21, 2023 to ask for a hearing before the full Ninth Circuit Court. Sections of Judge Berzon’s dissent will likely be part of any appeal. Berzon specifically addressed the overbreadth question. “Much honking is just noise, not First Amendment-protected communication. The obvious way to eliminate the statutory overbreadth as applied to First Amendment-protected honking is to except such beeping from the statute’s reach.”

David Loy, the First Amendment Coalition’s legal director, indicated to the Courthouse News Service the decision involved broader issues.

“I think this is a core First Amendment issue. People do this every day,” Loy said. “This is a significant cutback on the exercise of core free speech rights.”


Scott Bomboy is the editor in chief of the National Constitution Center.