Sonoma County may soon turn its back on 100 miles of rural roadways.

On Tuesday, the Board of Supervisors will consider stopping maintenance on certain roads to save an estimated $843,000 a year in manpower and material, though at the risk of significant inconvenience to some.

"Once we take roads off the maintenance system we are not allowed to spend money on those roads," said Phil Demery, the county's director of transportation and public works. "So if you had a minor landslide on a road, we couldn't spend any money on that."

The proposal comes as supervisors weigh ways to close a $43 million gap in the county's $379 million general fund.

The change would target low-volume byways used by less than 400 vehicles a day, provided that property owners along them have other means of access, Demery said.

But it's unclear exactly which roadways would be included. Demery would not give examples of affected roads, saying the list was still being developed.

If adopted, the proposal would mark the second major shift in road care priorities in the county in less than a year.

Last fall, supervisors conceded they lacked the money to maintain the county's 1,384-mile road network, the largest in the Bay Area. Instead, they opted to focus funds on 150 miles of the county's most travelled arteries, leaving the rest to languish with only cursory care like pothole patching.

Some supervisors, though, are now concerned about creating a third class of roads that get no attention at all.

Supervisor Mike McGuire, who represents northeast Sonoma County, said he was opposed to the scale of the proposal. Rural areas have long been contending with poor roads — this would only add to the woes.

"The potential recommendation would make a bad problem worse," he said. "It's going to be difficult for me to support that entire reduction."

His concerns were echoed by Supervisor David Rabbitt, who represents southwest Sonoma County. He said he's loathe to give up on infrastructure without a definite plan to return it to the maintenance system in the future.

But Supervisor Shirlee Zane, whose district is largely urban, said that maintaining lightly traveled roads was not near the top of her list of proposed cuts she wants restored.

"Given all the rest of cuts, I just don't see it as a higher priority," she said. "My priorities are going to be public safety and our most vulnerable populations."

Chris Hanlin, who lives on Sonoma Mountain Road, is already frustrated by the level of maintenance he experiences. Further downgrades strike him as absurd for an affluent county.

"If they really want to do this, I think they should give tax breaks to everyone who is living on this road to the tune of a new set of tires and a new set of brakes and shocks every year," he said.

Even if supervisors give their blessing to the idea, the public would have an opportunity to review the plan at a future hearing. All affected property owners would be notified of the hearing in advance.