With the passage of SB-45, the California Street and Highway Code was amended to transfer the programming and funding responsibilities of the Post 1989 Soundwall Retrofit Program to Regional Transportation Planning Agencies. In Los Angeles County, Metro assumed this responsibility. The eligibility determination as well as design and construction responsibilities for the program remained with Caltrans. Metro inherited a backlog of soundwall projects totaling nearly $1 billion without any corresponding funding from the State.
The Metro Board adopted the “ Soundwall Implementation Policy ” in January 2000. This policy contains a process for prioritizing, funding and constructing the Post 1989 Soundwall Retrofit Program in Los Angeles County. As of 2017, there are approximately 230 miles of freeways that are eligible for soundwalls. The Post 1989 Soundwall Retrofit list keeps growing as traffic, the number of trucks and the resulting noise levels substantially increase. New soundwalls are added to the eligible list based on preliminary field tests conducted by Caltrans at the request of residents and local agencies.
Through the adoption of the 2009 Long Range Transportation Plan and Metro’s 30-year Transportation Plan, Metro Board planned to fund the Post 1989 Soundwalls Retrofit Program. So far, soundwalls through Phase 1, Priority 2, Package 11 have been funded.
The design and construction cost of soundwalls are estimated at $10 million per mile on the freeway shoulder and $20 million per mile if placed on a structure (2017 estimates). Currently, over $2 billion is needed to design and construct the soundwalls on the existing Post 1989 Soundwall Retrofit Lists.
In order to implement the eligible and funded projects, Noise Barrier Scope Summary Reports (NBSSR) including a Noise Study, Environmental studies, preliminary engineering, and Right of Way Assessments are conducted. The project then advances through final design and construction. As of July 2017, NBSSRs have been completed for 42 miles of high priority soundwalls (through Phase1, Priority 2, Package 14).
Metro is currently seeking funds for implementation of more soundwalls in Los Angeles County. The order of priority of implementation of soundwalls will be Phase1, Priority 2, Packages 12 to 14; Phase 1, Priority 3; and ultimately Phase 2 soundwalls. However, the soundwalls currently on the lists, as well as those walls that might be added in the future, may be constructed out of order if they are part of a freeway capacity enhancement project (widening, Carpool lanes, ExpressLanes, etc.).