To: Board of Supervisors
Department or Agency Name(s): Public Infrastructure
Staff Name and Phone Number: Johannes J. Hoevertsz, 707-565-2550
Vote Requirement: Majority
Supervisorial District(s): Countywide
Title:
Title
Road Centerline Striping for North and South Fitch Mountain Roads
End
Recommended Action:
Recommended action
Approve a Modified Road Centerline Design for Portions of North and South Fitch Mountain Roads as Authorized by the California Traffic Control Devices Committee.
end
Executive Summary:
The Sonoma County Public Infrastructure Department (SPI) recommends approval of a modified centerline striping design for the pavement treatment project on North and South Fitch Mountain Roads in order to enhance vehicular safety along these narrow rural roads.
The California Department of Transportation has adopted uniform standards for road lines and markings, as well as other traffic control devices. These standards are published in the California Manual on Uniform Traffic Control Devices (CA MUTCD). SPI proposes a modification to the standard centerline designs for the two direction no passing pattern with markers specified under Detail 22 of Figure 3A-104 (CA) of the CA MUTCD. The proposed Detail 22A (attached) is similar to Detail 22 but replaces the two parallel retroreflective markers with a single marker placed in the center of the two 4” yellow lines. This modification allows a high visibility centerline with markers to be applied using minimal lane space, minimizes maintenance burdens, and increases vehicle safety by giving drivers more room to navigate the narrow roads with less instances of tracking over the raised pavement markers.
Section 1A.10 of the CA MUTCD provides a process for requesting permission to experiment with traffic control device design. SPI has followed this process, and on May 4, 2023, obtained approval to implement Design 22A on North and South Fitch Mountain Roads from the California Traffic Control Devices Committee (CTCDC).
Discussion:
The Fitch Mountain community near Healdsburg in unincorporated Sonoma County contains over 450 residences and public access to the adjacent Russian River served by the contiguous South Fitch Mountain Road and North Fitch Mountain Road. Both roads are Major Collectors, shaded under dense tree canopy, winding, and narrow ranging from 8’ to 9.5’ lanes.
South Fitch Mountain Road has a measured 85th percentile speed of 29 MPH with 478 Average Daily Traffic. North Fitch Mountain Road has similar conditions with a measured 85th percentile speed of 27 MPH, but more travelled with a measured 1105 Average Daily Traffic during the most recent engineering traffic survey.
Visibility is a critical concern on these roads especially at night. Between February 2020 and December 2022 there have been four reported collisions and numerous reported near misses, each occurring during the night hours. The roads are particularly difficult to navigate during rain and fog, which is common in the winter.
Although centerline striping with raised reflectors is not mandated by the CA MUTCD 3B.01, department engineering staff determined it would contribute to the safety of these roads. The applicable standard options for centerline striping are presented in Figure 3A-104 (CA) in the CA MUTCD.
Detail 22 from 3A-104 (CA) allows for the reflective markers to be placed on the striping; however, due to the narrow lanes, vehicles are more likely to track over the raised pavement markers, thereby creating hazards for drivers, increasing the likelihood of the raised pavement marker becoming dislodged, and creating nuisance noise to adjacent residences. Placing markers on the painted stripe also creates a maintenance issue when re-striping the road.
SPI proposes to modify standard Detail 22 for the pavement treatment project on portions of North and South Fitch Mountain Roads. The proposed modification is specified in Detail 22A, attached, which is very similar to Detail 22 but replaces the two parallel retroreflective markers with a single marker placed in the center of the two 4” yellow lines. This modification allows a high visibility centerline with markers to be applied using minimal lane space, minimizes maintenance burden, and allows drivers more room to navigate the narrow roads. This modification was developed after standard striping was applied and drivers were observed avoiding the markers causing unsafe lane departures.
SPI will collect data and provide reports for a 3 year period on the experimental design to the CTCDC pursuant to the approved request for permission to experiment as required under the CA MUTCD.
North and South Fitch Mountain Roads were included in the Roads Division 2021 and 2023 PPP. Work completed includes grinding, paving, and drainage improvements, as well culvert and guardrail replacements along approximately 2.7 miles of County owned roadway. With construction complete SPI is requesting Board approval of the modified centerline striping plan so the project can be completed. The County has authority to place lines, markings and other traffic control devices on its county roads under Vehicle Code Section 21351.
Strategic Plan:
N/A
Racial Equity:
Was this item identified as an opportunity to apply the Racial Equity Toolkit?
No
Prior Board Actions:
None.
Fiscal Summary
|
Expenditures |
FY23-24 Adopted |
FY24-25 Projected |
FY25-26 Projected |
|
Budgeted Expenses |
$10,480 |
|
|
|
Additional Appropriation Requested |
|
|
|
|
Total Expenditures |
$10,480 |
|
|
|
Funding Sources |
|
|
|
|
General Fund/WA GF |
$10,480 |
|
|
|
State/Federal |
|
|
|
|
Fees/Other |
|
|
|
|
Use of Fund Balance |
|
|
|
|
General Fund Contingencies |
|
|
|
|
Total Sources |
$10,480 |
|
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Narrative Explanation of Fiscal Impacts:
Expenditures for the proposed centerline installation are estimated at $10,480. Appropriations were included in the FY 2023-24 Roads Capital adopted budget (11051-34010103) and will be funded with the FY 2023-24 annual Pavement Preservation Program funds, sourced from local and state funding.
Narrative Explanation of Staffing Impacts (If Required):
None.
Attachments:
Detail 22A - The Fitch Mountain Centerline
Related Items “On File” with the Clerk of the Board:
None.