The closure will begin at 9 p.m. Friday, June 28 with all lanes open again by 5 a.m. Monday, July 1

PORTLAND — Four miles of Interstate 5 in Southwest Portland will close in all directions this weekend, Friday, June 28 to Monday, July 1 while crews rebuild the overpass across Southwest 26^th Avenue.

The closure will begin at 9 p.m. Friday, June 28 with all lanes open again by 5 a.m. Monday, July 1.

The I-5 closure comes as the U.S. Olympic Track & Field trials wind up Sunday in Eugene. Travelers going to or from the Olympic trials should plan for extra travel time or find alternate routes if their trip takes them through Southwest Portland.

Work on the project began over a year ago using a construction method that builds the new bridge underneath the existing bridge, which has allowed Interstate 5 to remain open for all but this one weekend.

This approach saves an estimated $5.5 million in costs and six months of construction time. It reduces the impact on traffic, reduces nighttime noise, reduces the environmental impact and improves safety for workers and drivers.

For more information about why we chose this construction method, see this fact sheet.

The I-5 bridge over 26th Avenue was built in 1959 and widened in the 1980s. It carries more than 100,000 vehicles per day and its deck is heavily worn and near the end of its useful life. This project will create a smoother ride for travelers while bringing it up to today’s seismic standards.

As a detour around the closure, traffic can use major Portland area highways including Interstate 205, Interstate 84, OR 217 or U.S. 26.

Southwest Barbur Boulevard will be available for local traffic.

In addition, to better manage traffic and ensure users don’t enter the closure area, the following Southwest Portland on-ramps leading to I-5 will close during the same times.

Northbound on-ramp closures:

• Southwest Kruse Way.
• Southwest Haines Street.
• Southwest Capitol Highway.
• Southwest Spring Garden Street.
• OR 99W/Barbur Boulevard.

 Southbound on-ramp closures:

• Interstate 405 on-ramp.
• South Harbor Drive on-ramp.

The project may include occasional nighttime single and double lane closures in both directions in the months ahead. Those closures have not been scheduled.

Work began on the I-5 bridge over a year ago. This project will improve the I-5 bridge in both directions over Southwest 26th Avenue with a rebuilt structure and will upgrade Southwest 26^th Avenue under the interstate with better lighting, bike lanes and sidewalks.​ 

For more information go to our I-5 Over 26^th Avenue Improvements project web site.

​The estimated project cost is $13 million.

Information provided by the Oregon Department of Transportation.