By Robbie Webber
The Presidio Parkway Phase I in San Francisco is the first state highway to be awarded a Greenroads certificate, indicating a high level of environmental sensitivity and sustainability during design and construction of the roadway. The project received a Bronze Rating.
For years Doyle Drive, part of U.S. Highway 101, ran through the Golden Gate National Recreation Area and connected the Golden Gate Bridge to the city street network. It also loomed as a viaduct barrier between the Presidio and the waterfront east of the bridge. Built in 1936, it was deteriorating and seismically unsound.
Through many public meetings and a multi-agency partnership, a design emerged that would allow two park connections on top of cut-and-cover tunnels—one between the Main Post area of the Presidio and the waterfront and the other between the San Francisco National Cemetery and Crissy Field. Other areas of what became the Presidio Parkway were brought down to grade to reduce the visual impact. From the beginning of the process, sustainability and context sensitivity were critical factors for this iconic location.
Key elements recognized by Greenroads in the project’s certification included an extensive public involvement process with special attention paid to biological, cultural, and natural resources. “This project earned very high marks for the context sensitive design,” said Jeralee Anderson, Greenroads Executive Director. “It is a challenge to rebuild complicated infrastructure in a dense urban environment with active traffic. The team made several good choices early on in the project development to position the project to be successful, including specifying certain plans were in place to help mitigate the impacts of different construction activities throughout the work, like waste and recycling, noise control, and construction quality.”
The Greenroads Rating System is a collection of sustainable roadway design and construction best practices that address water, environment, access, community impact, construction practices, and materials. To date Greenroads Foundation has certified 20 street and highway projects in the U.S. and Canada.
Buoyed by their success, Caltrans has set its sights on a Silver Rating for Phase II of the project, which completes the southbound connection to local streets and builds the northbound lanes of Highway 101, including three new cut and cover tunnels. Phase II is expected to be completed in 2016.
Robbie Webber is a Senior Associate at SSTI.
By Robbie Webber