Sound walls
Location details
The project includes three sound walls. This was determined by a vote among eligible residents and property owners.
One sound wall is being constructed in the first phase near the southbound lanes of I-205 at exit 9.
Two sound walls will be constructed in a future phase next to the southbound lanes of I-205 near Blankenship Road in West Linn, pending completion of the I-205 Toll Project Environmental Assessment.
How were the project’s potential sound wall locations selected?
The noise study analyzed the entire seven-mile project area and five locations along I-205 met ODOT and the Federal Highway Administration’s sound wall requirements: one along the southbound lanes of near exit 9, two near Sunset Avenue and two near Blankenship Road. See proposed sound wall locations below.
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When we increase the capacity of a freeway by adding lanes, the ODOT Noise Manual requires a noise study to determine if a sound wall would reduce highway noise. If the study determines a sound wall would reduce noise, ODOT considers constructing one.
A noise study was conducted for the I-205 Improvements Project, which determined adding a third lane in each direction on I-205 would slightly increase noise levels. This led to the consideration of five noise walls, three of which were supported by affected property owners and residents; these sound walls are included in the project. Generally, these three sound walls will range from 8–18 feet in height (subject to topography) and vary in length based on needs at specific locations. Sound walls are usually constructed at the very edge of the roadway to maximize noise reduction. The walls are typically made of concrete post and panel, concrete masonry block or steel panels (see example below). Final selection for the sound wall materials will occur later in the project.
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After the potential sound wall locations were identified, a vote among “benefitted property owners and residents” was required to determine if the sound walls were included in the project. As outlined by ODOT and FHWA, benefitted property owners and residents include anybody who lives at or owns property where a proposed sound wall would reduce noise levels by five or more decibels. If voters submit more “YES” votes than “NO” votes, the sound wall is included in the project. If there is a tie or fewer “YES” votes than “NO” votes, the sound wall is not included in the project.
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In 2019, eligible property owners and residents in West Linn voted on four proposed sound walls, two near Blankenship Road and two near Sunset Avenue. Voters supported the two sound walls near Blankenship Road that are now included in the project; the other walls were not supported and are not included in the project. In 2021, eligible property owners and residents in Oregon City voted to include a sound wall near the southbound lanes of I-205 at exit 9.
