On Sonoma Mountain Road off Adobe Road in Petaluma, a pickup speeds down a dirt section of the road much faster than the 15-mph speed limit. Road crews blame speeding vehicles for the road's washboard look and related bumps.Click to enlarge. Road Warrior photo

Sonoma County’s test of dirt roads is heading into what may be its final stage.

Next week, the county roads department plans to “armor coat” three sections of Sonoma Mountain Road that two summers ago it ground up, pulverized, injected a hardening enzyme into and compacted, leaving a hard-surface yet dirt road. The purpose was to see if roads in poor condition could be improved without having to be completely rebuilt.

Rob Houweling, operations coordinator for the county Department of Transportation and Public Works, said the test sections have “held up very well,” but he said the agency has no plans to grind up more rural roads. Instead, he said, the department will keep the process as an option for future repairs.

Last week, crews graded, reshaped and re-compacted a 600-foot stretch of Sonoma Mountain Road between Pressley and Enterprise roads, above Bennett Valley and Kenwood. This week, they will do the same on two sections of Sonoma MountainRoad off Adobe Road in Petaluma, Houweling said. Then on Aug. 9 and 10, crews will chip seal each of the three stretches twice – the armor coating.

For Craig S. Harrison, who lives off Sonoma Mountain Road in the Bennett Valley area, the chip sealing has been a long time in coming.

“We’re really happy that they’re doing that,” he said.

Harrison, a founder of the relatively new group Save Our Sonoma Roads, said the dirt section has been “a sore point” for nearby residents because of the dust created when cars and trucks pass over it. Some neighbors’ asthma has been aggravated, he said.

He said he doesn’t object to the county grinding up more roads as long as it chip seals them, giving them a hard protective cap.

For rural areas, “the county is never going to give us perfect roads, but if they can make them better, we’ll be happy,” Harrison said.

Houweling said the county initially planned to chip seal the Sonoma Mountain Road sections last summer but budget cuts put that on hold.

He said the sections have taken on somewhat of a washboard look, but he blamed that on drivers going much faster than the posted 15-mph speed limits.

To read an earlier column about the test sites, CLICK HERE.


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