Petaluma residents whose homes abut Highway 101 are soon to get some relief from the noise and potentially more dire nuisances that come with having a freeway in one’s backyard.

Sonoma County transportation officials this week voted to expedite a sound wall project along Highway 101 in Petaluma. The sound walls were originally included in a project to widen the freeway from Caulfield Lane to Corona Road, but that work has long been stalled due to an $85 million funding gap.

A fire in September that originated from a cigarette butt tossed from the freeway and burned 14 homes in an east Petaluma neighborhood prompted officials to separate the two projects and do the sound walls first while searching for funding for the highway widening work, according to Kathy Miller, a Petaluma city councilwoman and member of the Sonoma County Transportation Authority.

The fire torched a row of eucalyptus trees that had acted as a buffer between the houses and the freeway.

“After the fire, I went out touring the trees that were left and said that these trees are not safe and need to come down,” Miller said. “The neighbors were happy that the trees were down, but they were completely exposed to the freeway.”

The $12 million sound wall project is funded in part by a $7 million loan from the city of Petaluma to the SCTA. The city funds come from money set aside to build the Rainier crosstown connector, a long envisioned project that can only be built after the freeway is widened including a corresponding overpass. Once the freeway widening money is available, the SCTA is obligated to repay Petaluma’s money.

“Petaluma cooperated,” said Supervisor David Rabbitt, an SCTA member. “We borrowed the money from their project that was just sitting there. We’re moving money around.”

The 1.8 miles of sound walls will be in four locations, mainly along residential neighborhoods. A wall is planned along northbound Highway 101 just south of Corona Road; walls are planned along both sides of the highway just north of East Washington Street; and another is planned along the northbound highway between Caulfield Lane and East Washington Street.

With Monday’s approval, work will now begin on designing the walls and securing right of way. The construction contract is expected to be put to bid in late 2018 with work wrapping up in late 2019.

Officials are hopeful that highway widening funding will become available by then with construction work on the freeway through Petaluma complete by 2023. Officials are eying new state gas tax money and a possible extension of the Measure M sales tax in 2018 to complete what is the last gap in carpool lanes on Highway 101 from the Marin County line to Windsor.

Miller said doing the sound wall phase of the project first will mean it will be completed at least four years ahead of the freeway widening.

“It’s a little bit of an improvement,” she said.

(Contact Matt Brown at matt.brown@arguscourier.com.)