You have questions, the Road Warrior seeks the answers. Here’s a question from a reader and a response from the county roads department:

Question:

I live in the Larkfield Wikiup area of Sonoma County and have watched the repaving work on Old Redwood Hwy from north of the city limits through Larkfield. My concern, and maybe you know this already, is why is the “new” road surface so rough? The chip seal rock is huge and extremely abrasive. Just like out on Occidental Rd. near High School Rd. in Sebastopol. The bike lanes are left with the old surface, which was not in that bad a shape to begin with. Why here and now, since the road was not that bad off, and why the poor quality surface material? Todd

Answer:

Thank you for forwarding this question to us. In regard to the writer’s concerns about the relative surface roughness of the work the department is currently conducting on Old Redwood Highway, I suspect that the writer observed the work before the contractor had finished.

The project that the department is currently constructing on Old Redwood Highway, and recently finished on other roads such as Dry Creek Road, Alexander Valley Road and Westside Road, have been resurfaced with an asphalt rubber “double” chip seal. This is a pavement preservation process that uses two separate chip seal applications. The first layer uses a ½” aggregate that is applied to the travel way, which as your reader notes is very rough. That ½” base chip seal is followed by the second ¼” inch chip seal, that is applied to the entire road section. This system provides smooth surface texture.

Sustainability is a term not generally associated with road construction and maintenance. Sonoma County is working hard to change that perspective with projects that focus on pavement preservation. Global concerns about climate change, energy use, environmental impact, and limits to financial resources for transportation infrastructure require new and alternative approaches to planning, designing, constructing, operating and maintaining transportation systems. We are continually seeking new solutions to reduce the impact of transportation on our environment by employing new technology and methods to traditional practices.

The chip seal projects constructed on several county roads, including the work Old Redwood Highway this summer are examples of the pavement preservation program being implemented by Sonoma County’s Department of Transportation and Public Works (DTPW). Historically, DTPW has been like many agencies, responsible for managing road infrastructure systems. Maintenance work would often wait until deficiencies became apparent even to the untrained observer, which meant that road maintenance activities were being applied reactively to roads in poor condition rather than proactively to roads in good condition. That approach was expensive and ineffective, both from a financial and resource management perspective. By adopting a pavement preservation approach that proactively addresses minor deficiencies and repairs early, the service life of our roads can be substantially increased, in a more cost effective manner and avoid the more costly rehabilitation and material intensive treatments.

The department’s road maintenance activities are funded by state and federal gas taxes. Although some of our funding is collected through our local Measure M sales tax, it provides less than 10% of our annual road maintenance budget. Gas taxes are not a sustainable revenue source for road maintenance. Not only are the taxes not indexed, meaning that the tax amount remains flat regardless of the selling price of fuel, but they do not account for energy efficient vehicles, alternative fuel vehicles, and other users of the road, such as bicyclists.

Given the department’s budget realities today, our primary goal is to protect the public investment and extend the life of the county’s infrastructure. The various treatments used to preserve pavements, such as chip seals, do a good job of protecting the roadway, but they are not necessarily designed to make the road smooth, as you point out in your email. Our county road quality is degrading, and unless we take advantage of these more cost effective measures, parts of our road system will revert to gravel in fewer than 10 years. Given our declining revenues and exponentially increasing costs, the treatment recently placed on Old Redwood Highway and others road was the best solution out of many alternatives considered for the road’s pavement condition, traffic and environmental setting.

We realize that some of the preservation treatments we use may not fulfill all expectations the public may have, but we want you to know that we appreciate your input as we work to keep our infrastructure working for everyone throughout Sonoma County.

Stephen B. Urbanek
Pavement Preservation Manager
Sonoma County Department of Transportation and Public Works