Some noisy vehicles are illegal, but it’s hard to enforce

A blast from a loud exhaust of a passing motorcycle can rattle more than just nerves or leave ears ringing.

“The noise almost gives me a heart attack,” my colleague Sue Misao, who works on The Daily Herald’s digital desk, told me.

She came to me with her own Street Smarts question and had me wondering, too.

What does the law say about ear-splitting motorcycles? And what, if anything, can be done to tamp down on the racket?

According to Washington state law, drivers cannot “modify the exhaust system of a motorcycle in a manner which will amplify or increase the noise emitted by the engine of such vehicle above that emitted by the muffler originally installed on the vehicle.”

Basically, if someone alters the exhaust in a way that makes it louder than when it left the factory that’s a violation, said Sgt. Darren Wright of the Washington State Patrol.

But this law is difficult to enforce at times because it’s hard to determine what systems have been modified, he said, therefore not many tickets are issued.

Courtney O’Keefe, a spokesperson for Snohomish County Sheriff’s Office, agreed with Wright that implementation of noise laws are difficult.

She pointed to a county law that sets maximum sound limits. (It’s similar to an existing state law.)

“It is based on decibels,” she said in an email, but “deputies do not have an easy method for measuring that.”

The limit ranges from 72 to 90 depending on the vehicle and speed it is going. For some comparison, gas-powered lawnmowers and leaf blowers emit at levels between 80-85 decibels, according to the Centers for Disease Control and Prevention. Keep in mind though, the decibel scale is logarithmic, not linear, so the intensity of a sound grows very fast.

In an effort to make it easier for police to cite drivers with excessively loud exhausts, Seattle recently took a different approach.

The law, which passed last year, allows officers to issue tickets if exhausts “can be clearly heard by a person of normal hearing at a distance of 75 feet or more from the vehicle itself.”

Got a question? Email me at streetsmarts@heraldnet.com or call 425-374-4165. Please include your name and city of residence.