Soundwalls: Frequently Asked Questions

1. What are soundwalls?

Soundwalls are barriers constructed of a solid material designed to prevent or reduce the transmission of noise. They are typically built between the freeway and adjacent properties. Soundwalls are designed and constructed using Caltrans specifications and are maintained for structural integrity by Caltrans.

2. Will soundwalls be built as part of the I-15 Express Lanes Project?

Yes. As part of the environmental review process required for state highway projects, the Riverside County Transportation Commission (RCTC) and Caltrans evaluated traffic noise along the project corridor. Based on the studies conducted, six soundwalls will be built along the southern portion of the project corridor. A map of the soundwall locations is available on the project website,

3. What are the criteria for approving a soundwall?

RCTC and Caltrans follow state and federal policies and criteria to determine where soundwalls are built. The primary criteria include:

  • The noise at the affected properties must exceed a minimum level, which is an average of 67 decibels for outdoor use areas; this equates to noise heard 100 feet from a freeway or 10 feet from a vacuum cleaner.
  • The proposed soundwall must be effective in reducing freeway noise by at least 5 decibels.
  • Soundwalls must not exceed a state-established construction cost maximum of $92,000 per property.
  • Property owners who will benefit from soundwalls must support construction of the wall through a survey. The majority of residents must agree to construction of the wall.

Other factors considered include engineering challenges, such as driveway access, underground utilities, safety elements and input from the public and public agencies. For more information, visit

4. How will I be affected during soundwall construction?

In order to build soundwalls next to private property lines, RCTC has obtained temporary construction easements from affected property owners. These easements provide access and space for the contractor to safely build the walls, and RCTC compensates property owners for the temporary use of land and will restore affected areas. Every effort is made to reduce disruption to residents during construction of the walls.

5. What is the design of the soundwalls?

The soundwalls will be built using concrete split-face block and will range in height from approximately 14 to 16 feet. Soundwalls will be designed to be visually compatible with the surrounding community character and consistent with the State Route 91 Corridor Improvement Project Aesthetics and Landscape Master Plan. Wall aesthetic treatments will be reviewed and approved by the Caltrans Landscape Architect.

6. When will the soundwalls be built?

Construction of the soundwalls is planned to be completed in 2018 and 2019, prior to construction of the I-15 Express Lanes in this area. To stay informed of overall project construction, please sign up to receive construction updates at


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