Project Selection

Making the most of limited funding

The Department of Transportation & Public Works is responsible for maintaining about 1,379 miles of roads outside of cities in Sonoma County.

It would cost $58 million every year for 10 years to bring these roads to a level where they can be maintained at a lower cost through best management practices. Sonoma County is not alone, it would cost $7 billion every year for 10 years to bring all local roads in California into this condition.

From 2012 - 2017, the Board of Supervisors (Board) dedicated over $65 million local dollars to paving. This investment will contribute to paving about 300 miles of roads. Roads are typically funded with state gas tax, however for years the state gas tax did not fully covered mandatory maintenance, and left no money for paving.

Sonoma County is one of the leading Counties in the State of California to dedicate local, discretionary General Fund dollars to roads. In 2017, the State Legislature approved new funding for roads, which will raise our total state revenue to over $20 Million when fully phased in, more than double the current allocations from the State.

Despite this contribution of local funds and new state gas tax, there is still a significant funding shortfall for roads. With such an extensive road system and limited funding sources, we must strategically select roads for pavement preservation treatments.

How are roads selected?

A list of roads is developed every year, to be resurfaced during the following year's Pavement Preservation cycle. The selection process takes multiple criteria into consideration, including pavement condition, type and amount of usage, design characteristics, as well as geographic distribution of projects. These factors are described in the next section, and the Long Term Road Plan (PDF).

Selection Criteria

Pavement Condition

County roads are periodically inspected and assigned a score, called Pavement Condition Index (PCI), which indicates pavement condition on a scale of 0 to 100 (100 being the best).

PCI scores are entered and tracked in a computer program that uses a complex algorithm to calculate the most efficient usage of available funds on a system-wide basis; that is, which roads to treat and which treatments to use in order to achieve the highest possible increase in pavement life-span. We use a combination of treatments which purposes range from rebuilding roads that have reached the end of their life span to preserving roads that are in relatively good condition.

See map of pavement condition on Sonoma County roads

Usage and Functionality

The way a road is used, and the amount that it is used, are the primary factors in determining the function of a road. This is measured using traffic volume, and factors such as connectivity between communities, vital routes to the local economy, connectivity for transit and bicycle routes, and usage for emergency services.

The State of California classifies all public roads according to these factors; this classification scheme is referred to as Functional Classification.

See map of Functional Classification on Sonoma County roads

Design Characteristics

The way a road is designed determines the cost of treating it. Characteristics that get considered include road width, the structural foundation, type of surface material (asphalt, concrete, gravel, etc.), and whether any pedestrian features (sidewalks, ramps, etc.) are present that would require ADA (Americans with Disabilities Act) compliance.

Geographic Distribution of Projects

Project funds are allocated with an equitable geographic distribution across the County.

See current and upcoming projects

See completed projects

    Worst First: Low Volume Roads

    The criteria for selecting roads ensures that priority will be given to roads that have high usage and functionality. Recognizing that this excludes many low-use residential and rural roads, the Board of Supervisors dedicates $1 Million per year to lower-volume roads. These roads are selected using a combination of feedback from the Road Maintenance Division, constituent feedback shared with Transportation and Public Works and the Board of Supervisors, and calculations that include factors like pavement condition.

    Contact Information

    Business Hours
    Monday – Friday
    8:00 AM – 5:00 PM
    Contact us by Phone
    Office Location
    La Plaza B
    2300 County Center Drive
    Suite B 100
    Santa Rosa, CA 95403
    38.462023, -122.725381

    More Information about Pavement Preservation

    Interactive Maps

    Sonoma County Interactive Maps


    Thematic interactive maps for Sonoma County