1. Home
  2. Caltrans Near Me
  3. District 11
  4. Current Projects
  5. I-805/SR-15 Transit Only Connector and Managed Lanes Project
  6. Sound Wall FAQ’s

Sound Wall FAQ’s

Who decides where a sound wall is recommended? 

Answer: The Federal Highway Administration (FHWA) requires that Caltrans study traffic and construction noise impacts before beginning a project. Noise studies are coordinated with the environmental review process for a project. The results of the studies are used by Caltrans, in consultation with the FHWA, to determine where a sound wall is recommended. 

Where are the potential noise impacts studied? 

Answer: Noise studies measure the existing and future predicted traffic noise levels near homes, schools, churches, recreation areas, libraries, hospitals, motels, residential and commercial properties. Noise measurements are taken at exterior areas where people frequently gather. 

What factors determine whether a sound wall is feasible/reasonable? 

Answer: Various factors such as topography, access, local streets, underground utilities, other noise sources and safety are studied when proposing a sound wall location. To be feasible, sound walls must reduce noise by at least five decibels. A sound wall is determined to be reasonable based on cost, input from affected property owners and the structure’s useful life. 

Where can transparent sound walls be built? 

Answer: Transparent sound walls can only be constructed on private property. Property owners may request transparent sound walls to preserve views. Masonry block walls are constructed on private properties where views are not a concern. 

Is there a different process for building a sound wall on private property versus in the public right-of-way? 

Answer: Without public consensus, Caltrans may not proceed with a wall. To build a sound wall on Caltrans right-of-way, 50% of affected property owner must agree to the wall. To build a sound wall on private property, 100% of affected property owners must agree to the proposed wall location, materials and agree to maintenance. To receive a sound wall on private property, the property owners must: 

  • Enter a contract with Caltrans that outlines each parties’ responsibilities.
  • Accept the wall footing within their property by permanent easement in the State’s name. 
  • Accept aesthetic and ordinary maintenance responsibility for both sides of the sound wall. 
  • Execute a Memorandum to capture the maintenance obligations as covenants running with the land and be binding on subsequent purchasers, assignees, or successors. 

What type of outreach does Caltrans conduct to try and get consensus from residents? 

Answer: A significant effort is employed to educate and inform residents about proposed noise mitigation measures, and to secure their feedback. This may include, sending letters to residents, door-to-door outreach, and public meetings where necessary. 

Does the construction of a sound wall affect the assessed value of a property? 

Answer: No. Walls built 100% within Caltrans right of way will not affect the property assessment. If a Temporary Construction Easement (TCE) on a property is needed to construct a wall, the TCE will not affect the property assessment. And if a portion of the wall or footing constructed on Caltrans right of way extends into private property, the State will acquire a permanent wall and/or footing easement. By doing so, the County will recognize the sound wall as owned by the State and not Owner, therefore, County will not reassess property.