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The Interstate 5 bridge over Southwest 26th Avenue was built in 1959 and widened in the 1980s. It carries over 100,000 vehicles per day. Its deck is heavily worn and near the end of its useful life. The project will maintain this important freeway connection and create a smoother ride for travelers while bringing it up to current seismic standards.
ODOT is working closely with the Portland Bureau of Transportation (PBOT) for the portion of the project on SW 26th Avenue. See more about this later in this online open house.
Construction Update
Work began on the I-5 bridge nearly a year ago. We're using a construction method that builds the new structure underneath the existing bridge while I-5 remains open.
This July, we’ll rebuild the top of the structure with a new asphalt road during the one-weekend closure of I-5.
The construction method selected allows I-5 to remain open for all but one weekend, lowers costs and construction time, reduces nighttime noise impacts, has lower environmental and traffic impacts, and improves safety for workers and travelers.
Read more about how we chose this construction approach in the next station.
Project Timeline
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Spring 2023: Construction began, SW 26th Avenue closed to motor vehicles for about a year and reopened on May 1, 2024.
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Summer 2024: One-weekend closure of I-5 in both directions for over 4 miles from June 28 to July 1. SW 26th Avenue will be closed again during this weekend closure. Sign up for project updates to learn more as we get closer.
Project Area
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How We Are Replacing The Bridge
Replacing a bridge is expensive, time-consuming and can be disruptive to traffic and the surrounding communities. To minimize impacts, we evaluated different options for replacing the I-5 bridge over SW 26th Avenue. The two most viable options were:
- Build a replacement bridge, which means building an on-site temporary detour bridge and shifting traffic to it during construction, creating major impacts on I-5 for almost two years.
- Build a new structure underneath I-5 and rebuild the roadway during a one-weekend closure of I-5 in both directions.
We chose the approach to build the new structure underneath I-5 and then rebuild the road above because it resulted in lower costs, shorter construction time, fewer traffic impacts, less nighttime noise in the community, fewer environmental impacts and improved safety for workers and travelers.
By replacing the bridge this way, we were able to keep I-5 open for all but one weekend, with only occasional nighttime single-lane and double-lane closures and up to 10 nights of either I-5 southbound or northbound closures. We also saved up to $5.5 million in construction and operational costs and reduced the construction schedule by half a year.
Learn more about why we chose this construction method here.
An improved SW 26th Avenue reopened May 1. It will be closed again during the weekend of I-5 closure. Read more about the improvements we made to SW 26th Avenue later in this online open house.
Crews building the new structure under I-5 on SW 26th Avenue.
The progress of the new structure walls on SW 26th Avenue. The new structure will look and feel like a tunnel when finished.
On Interstate 5
We will close I-5 in both directions for four miles from Friday, July 28 at
9 p.m. to Monday, July 1 at 5 a.m.
- I-5 southbound will close between Terwilliger exit ramp and Capitol Highway entrance ramp.
- I-5 northbound will close between Barbur Boulevard exit ramp and Terwilliger entrance ramp.
This closure allows crews to get as much done as possible during the one weekend I-5 closure. During this closure, the crews will remove the top of the existing roadway and add new asphalt paving. Many different types of work are needed to complete the bridge replacement. We chose this weekend when most crews are available to close I-5 and ensure that we can finish the bulk of this work during the one weekend closure.
To better manage traffic and ensure drivers don't enter the closure area, seven Portland on-ramps leading to I-5 will close during the same times.
Southbound on-ramp closures:
- S Harbor Drive.
- Interstate 405 southbound exchange to southbound I-5.
Northbound on-ramp closures:
- SW Spring Garden Street.
- SW Capitol Highway.
- OR 99W/SW Barbur Boulevard.
- SW Haines Street.
- Kruse Way.
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Detour Routes
As a detour around the closure, traffic can use major Portland area highways including Interstate 205, Interstate 84, OR 217 or U.S. 26. By directing regional travelers onto other Portland area highways such as Interstate 205 and OR 217, we’re reducing the volume of traffic heading towards the closure area to ease the impact on local roads. Congestion is expected during the I-5 weekend closure.
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A signed local detour will use SW Barbur Boulevard. This detour maintains local access.
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Additional Nighttime Impacts on I-5
To prepare for and finish the bridge replacement work safely with minimal traffic impacts, additional nighttime work is required on I-5. This will include I-5 lane closures. The following may be expected:
- Up to five southbound and five northbound nighttime directional closures on I-5 from 11 p.m. to 5 a.m.
- Nighttime double-lane closures on I-5 from 10 p.m. to 5 a.m. before and after the I-5 weekend closure.
- Nighttime single-lane closures on I-5 in both directions from 8 p.m. to 5 a.m. on weekdays and from 8 p.m. to 8 a.m. on weekends.
Nighttime Noise
Nearby neighbors may hear construction noise. We will use construction noise mitigation measures to reduce noise.
Use the 24/7 nighttime noise hotline to discuss any noise concerns: 503-276-7892.
Construction impact during the I-5 weekend closure
Last spring, SW 26th Avenue closed to motor vehicles from under I-5 to under Barbur Boulevard for the crews to begin building the new structure.
SW 26th Avenue reopened May 1 with new, wider sidewalks and accessible curb ramps. It will need to be closed again during the weekend I-5 is closed.
Crews have maintained a pathway for pedestrians and people biking through on SW 26th Avenue. The path shifts locations depending on construction activities and provides an inside look at the construction progress.
Path access under I-5 will be open throughout the rest of the SW 26th Avenue closure and during the I-5 weekend closure. Flaggers will be on site to direct pedestrians and people biking in case crews need to momentarily close the path for safety.
A newly paved SW 26th Avenue with the new structure, improved sidewalks and curb ramps.
An Improved SW 26th Avenue
An improved SW 26th Avenue reopened May 1 and it has the following improvements:
- A newly paved road.
- A newly built and painted structure with the sides filled in, similar to the look of a culvert or tunnel (see illustration). Light fixtures have been installed in the structure to ensure that it will be well-lit for the safety of people traveling through.
- New, wider sidewalks and bike lanes for people to walk, bike and roll.
- New, ADA-compliant curb ramps.
- The intersection of SW 26th Avenue and SW Barbur Court is upgraded with wider sidewalks and high-visibility crosswalks.
There are still a few items to finish on SW 26th Avenue, such as connecting the lights, final striping and planting vegetations, Boston Ivy (non-invasive), on the outside of the structure.
A sketch of the improvements on SW 26th Avenue and the new structure, viewed from SW 26th Avenue looking southeast.
Collaboration with PBOT
ODOT is collaborating with the Portland Bureau of Transportation (PBOT) on the project elements that affect SW 26th Avenue. This includes connecting to the new multiuse path PBOT is building as part of their OR 99W/SW Barbur Blvd Area Sidewalk Infill Project and adding new sidewalk to continue the connection north to SW Barbur Boulevard. ODOT will connect the end of that sidewalk project through this project’s area to SW Barbur Boulevard, thus ensuring continued pedestrian and bicycle infrastructure and connectivity along SW 26th Ave.
Questions or comments? Contact:
Ellen Waters, Community Affairs Coordinator
Ellen.WATERS@odot.oregon.gov | 971-336-1249
For ADA Title II or Civil Rights Title VI accommodations, translation/interpretation services or for additional information call 503-731-4128, TTY 800-735-2900 or use the statewide Oregon Relay Service: 7-1-1.
¿Habla ustéd español? Podemos proveer la información en esta publicación en español. Para recibir la información en español, por favor llamé al 503-731-4128.
Aerial view of I-5 over SW 26th Avenue during construction.