Miller Avenue Streetscape Plan with Full-Depth Reclamation (Overall Winner)
Location
Miller Avenue from Sunnyside to Almonte
City or County Responsible for Project
City of Mill Valley
Category
Roads: Efficient and Sustainable Road Maintenance, Construction and Reconstruction Projects.
Author
Andrew Poster
City of Mill Valley
26 Corte Madera Avenue
(415) 226-0823
Project Description
Miller Avenue functions as a central corridor serving the circulation, commerce, recreation, and experiential needs of Mill Valley’s residents and visitors. The Miller Avenue Streetscape Plan balanced the need to improve critical infrastructure and safety features while preserving the unique character of Mill Valley. The 2-mile thoroughfare is filled with unique character and five “rooms” that define the character and history of the street. The development of the Plan involved an extensive community-based planning process that incorporated multi-modal features along the corridor and highlighted historical conditions, surveyed community sacred places, identified minimal change options, evaluated existing trees and introduced water quality features to improve the quality of storm water released to the Corte Madera Creek Watershed. The Miller Avenue corridor was originally established with the railroad in 1889, leading to median parking to accommodate cars and the railroad. The Plan is the first comprehensive design for the street with a primary goal of creating a safe and efficient multi-modal corridor consistent with the Complete Streets principles of design, features to accommodate all users including vehicles, transit, bicycles and pedestrians. The Plan also improved the underground and roadway infrastructure, preserve and enhance the corridor experience (through planting new drought resistant landscaping and rain gardens to reduce peak storm discharge into nearby creeks), maintain cultural features of Mill Valley, and improve the overall infrastructure. A 1,700 foot stretch of the Project eliminated frontage roads, realigning the street to accommodate parking, travel lanes, accessible sidewalks and buffered bike lanes. Due to the large amount of reconstruction required, combined with elevation changes and difficult soil conditions, the roadway construction underwent a process known as “Full Depth Reclamation” (FDR), pulverizing 18 inches of the underlying roadway that is then reused for ground materials and overlaid with new asphalt. FDR is 50% less expensive than traditional road repair methods, reducing excavation as well as the import and export of materials. Although rarely implemented in an urban setting, the City was able to successfully apply this method of road reconstruction, lowering overall truck trips hauling materials in and out, and reducing the cost of replacing the pavement. This stretch of roadway is now uniform with a consistent cross slope, and offers a 20-year design life with regular maintenance. The FDR repaving work was conducted at night (7pm-8am), cutting the work time by 3-4 weeks, minimizing disruption to the community and businesses, and maximizing driveway access. The complete project supports the Transportation Authority of Marin’s “Safe Routes to School” program. A new wooden boardwalk and sidewalk provides a pleasant walk along a creek to connect downtown Mill Valley to an adjacent residential neighbo
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