Interstate 405

The initial section of Interstate 405 complete by 1967 encircled the city center northwest from Harbor Drive to Montgomery Street.

Interstate 405, known as the Stadium Freeway, is an urban loop encircling Downtown Portland to the west of the Willamette River. U.S. 26 overlaps I-405 to Sunset Highway while U.S. 30 runs concurrent with I-405 across the Fremont Bridge to I-5.

Interstate 405 was originally constructed with the intent to evenly distribute traffic around the downtown area between the two freeways that encircle central Portland. Through traffic could bypass the city center along I-5 to the east of the Willamette River. Construction on I-405 began in 1964, and the Stadium Freeway was built in two stages: everything except the Fremont Bridge opened on February 25, 1969, and the Fremont Bridge opened on November 11, 1973. I-405 was the single most expensive Interstate Highway construction project in Oregon, costing $121 million.

Interstate 405 Oregon Guides

North - 33 photos

South - 29 photos

scenes

An entrance ramp to Interstate 405 south lowers from NW 16th Avenue onto the Stadium Freeway two blocks south of Glisan Street in Portland..

06/24/15

NW 16th Avenue south intersects Everett Street at the entrance ramp to Interstate 405 south.

06/24/15

NW 15th Avenue heads two blocks north from Everett Street to the northbound entrance ramp for Interstate 405 at Glisan Street.

06/24/15

SW 14th Avenue spans Interstate 405 ahead of Burnside Street, where an access road branches westward to the entrance ramp at Couch Street.

06/25/15

Couch Street west at the northbound on-ramp for Interstate 405.

06/25/15

References:

• Andrew Fields

Connect with:

Interstate 5

U.S. 26

Page Updated Monday August 25, 2025.