Austin police officers will soon be able to fine motorists up to $500 for excessive engine noise following a unanimous Austin City Council vote Thursday.

The ordinance creates a new Class C misdemeanor for drivers whose vehicles emit noise exceeding 85 decibels or make sounds considered “offensive to a person of ordinary sensibilities,” giving officers broader authority to address what many describe as a growing problem on some roadways.

Council members approved the measure alongside an amendment requiring officers to issue a warning before writing a ticket — a change sought by the ACLU of Texas and backed by some members who raised concerns that the ordinance’s subjective enforcement standards could lead to inconsistent or discriminatory policing.

Adoption of the ordinance concludes a process that began in January when Austin Police Chief Lisa Davis asked City Council to develop the ordinance. Excessively loud vehicles has become a common nuisance across Austin, but a group of West Austin neighbors have pushed the city to take action.

The neighbors say that motorcycle enthusiasts regularly drive recklessly and noisily along RM 2222 west of Loop 360 and that officers have not been able to reign in the behavior under existing city rules.

City Council Member Marc Duchen, who represents the neighborhoods rallying for the ordinance, said the new rules would provide officers with a new tool for curbing dangerous driving behavior.

“We’re not targeting normal, everyday drivers,” Duchen said ahead of the Thursday vote. “We’re not targeting any particular kind of vehicle. We’re helping reduce noise from vehicles that are much, much louder than the average car.”

The ordinance allows officers to cite drivers for creating noise in excess of 85 decibels, but Assistant Police Chief JJ Schmidt told City Council Thursday that the Austin Police Department does not have many of the tools required to measure decibel levels and that most officers do not carry them.

The ordinance also allows officers to consider more subjective criteria before pulling someone over, such as: intensity of the noise, if the nature of the noise is unusual, proximity of the noise to residences, the time of day of the noise and whether the noise is recurrent.

Some justice advocates worry those subjective enforcement criteria could lead to inconsistent and discriminatory enforcement. In a letter to City Council, ACLU of Texas Senior Manager Nick Hudson wrote that although Class C offenses are “fine only,” they can turn into warrants when unpaid. That could cause a “devastating cascade of consequences” for lower-income Austinities, Hudson wrote.

Hudson urged council to curb potentially discriminatory enforcement of the ordinance by amending it to require officers to issue a warning before citing drivers. Council Member José Velásquez said he agreed with those concerns, especially for immigrants in Austin who are increasingly wary of contact with law enforcement during the second Trump administration.

“Right now, we have community members that are afraid to step out of their homes, send their kiddos to school and go to the store for basic needs,”  Velásquez said. “This new offense could exacerbate fear around using vehicles.”

City Council voted unanimously to adopt an amendment from Velásquez requiring officers to issue a warning to motorists before citing them for excessive engine noise.

In a Feb. 23 memo, Davis said officers would receive new training on how to enforce the ordinance and the Police Department would work to educate the community about the new rules. She also said there would be a 30-day grace period during which officers would have the discretion to issue verbal or written warnings to motorists instead of citations before the new regulation takes effect.