Two sound walls will be located next to the southbound lanes of I-205 near Blankenship Road in West Linn.
One sound wall will be located near the southbound lanes of I-205 at exit 9.
When ODOT increases the capacity of a freeway by adding lanes, the ODOT Noise Manual requires ta noise study. If the study indicates a certain level will be reached, ODOT assesses the benefits of constructing a sound wall. If the sound wall will reduce noise generated from the highway, ODOT considers construction of a sound wall.
A noise study was conducted for the I-205 Improvements Project, which determined adding a third lane in each direction on I-205 will slightly increase noise levels along the highway. This led to the consideration of five noise walls, three of which were supported by affected property owners and residents and 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.
The noise study analyzed the entire seven-mile project area and five locations along I-205 satisfied the ODOT and Federal Highway Administration 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.
After the potential sound wall locations were identified, a vote among benefitted property owners and residents was required in order 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 at which noise levels will be reduced by five decibels if the proposed sound wall is built. 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.
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.