Construction began in 1963, utilizing a trench with extensive landscaping and frequent overpasses, and was the most expensive freeway project in state history at a cost of $121 million.

Plans for a spur freeway, I-505, were cancelled in 1978 following public opposition; its interchange with I-405 was subsequently reused for a 1988 realignment of U.S. Route 30 (US 30), which runs concurrent with I-405 across the Fremont Bridge to I-5.

[4][5] US 26 splits from I-405 at an interchange north of Montgomery Street, traveling via the Vista Ridge Tunnels onto the Sunset Freeway towards the western suburbs of Portland.

I-405 then turns northeast and narrows to four lanes as it travels through the east edge of the Goose Hollow neighborhood, passing the Multnomah County Central Library, Lincoln High School, and Providence Park, home of several local soccer teams.

At Yamhill and Morrison streets, I-405 crosses under bridges carrying MAX Light Rail trains, which continues west towards Beaverton and east to Downtown Portland.

After an interchange with Glisan Street, the freeway becomes elevated and passes over cross-streets in the Pearl District, including those carrying the tracks of the Portland Streetcar's NS Line.

[11] The double-decker freeway continues northeast over the Union Pacific Railroad's Albina railyard and Interstate Avenue, a part of Route 99W that also carries the MAX Yellow Line.

[16] Highway planner Robert Moses was commissioned by the city government in 1943 to envision a program of public improvements that would begin after the end of World War II to provide employment for returning soldiers.

[23][24] The federal Bureau of Public Roads included the Stadium Freeway in its 1955 recommendation for a national system of expressways that were later funded by the Federal-Aid Highway Act of 1956.

[32] The Oregon chapter of the American Institute of Architects and several industry groups recommended a delay in deciding the route based on potential damage to the cityscape caused by the designs in both options.

[44][45] An estimated 554 buildings with 1,668 residential units were in the right of way for the freeway,[42] including a school, several churches, and a recently completed synagogue for Congregation Shaarie Torah.

[46][47] In 1963, the owner of the Carlton Hotel, a long-term care home with 139 elderly residents, appealed the condemnation and planned demolition of the building to make way for the Stadium Freeway.

[50][51] Further planning work was delayed by a dispute with the city government and Bureau of Public Roads over the location of ramps and interchanges in early 1961, which were resolved with formal federal approval in August.

[53] In February 1962, the Portland City Council postponed its decisions on closing streets for freeway construction and ratification of an agreement with the state highway commission on maintenance of ramps and overpasses after protests from local residents, who described I-405 as a "gigantic monstrosity" and the "West Side Suicide".

[54][55] The state highway commission halted its property acquisition negotiations the following month while awaiting the city council's approval of the agreement and other plans, which were required under federal law.

[61][62] The Stadium Freeway project was divided into several stages to reduce long-term disruption to cross-town access, beginning with the trenched roadway in the Foothills area with 19 overpasses and working northward.

[86][87] It included 22 overpasses to reduce disruption to the street grid and 55 retaining walls, which were covered by planted trees, shrubs, and ivy to beautify the freeway.

[9][89] The freeway's overpasses were opened to traffic in October 1968, but completion of the lanes and ramps was delayed over heavy rains that disrupted grading and installation of guardrails and signs.

[103][104] The unused ramps were instead redirected to Kerby Avenue to serve the expanded Legacy Emanuel Hospital with approval from the city council in 1974 despite protests from local residents, which stalled the project for several years.

[110] ODOT began a year-long project to repair and replace expansion joints on elevated sections of the freeway in March 2019 because of extended deterioration of the structure.