Sonoma County's test of turning paved roads into dirt is earning both an A and an F for durability.
Last summer, the county Transportation and Public Works Department took three pothole-patched stretches of Sonoma Mountain Road and after grinding, pulverizing, injecting a hardening enzyme and compacting, crews left a hard-surfaced, dirt road to see if it could improve poor roads without having to completely rebuild them. If the test is successful, department officials say, more of the county's rural roads will be turned into dirt.
A 600-foot segment between Bennett Valley and Kenwood appears to have survived the winter storms so far largely unscathed, with only a handful of tiny potholes. Definitely a success.
But to the south two other test stretches of Sonoma Mountain Road off Adobe Road near Petaluma are a mess, dotted here and there with significant potholes. Definitely a failure.
Rob Houweling, operations coordinator for the roads department, said the difference in how well the test sites are performing boils down to that asphalt grindings were incorporated into the Petaluma-area segments but not in the Kenwood-area one.