Interstate 405 (I-405), also known as the Stadium Freeway No. 61, is a short north–south Interstate Highway in Portland, Oregon. It forms a loop that travels around the west side of Downtown Portland, between two junctions with I-5 on the Willamette River near the Marquam Bridge to the south and Fremont Bridge to the north.
The Stadium Freeway was envisioned in the 1940s and 1950s by the state government and was added to the Interstate Highway system in 1958. 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. Hundreds of buildings were demolished to make way for the freeway, which displaced approximately 1,100 households.
The southernmost section of I-405 opened on October 26, 1965, and was followed by extensions in 1966 and 1969. The final section, including the Fremont Bridge, opened in November 1973. 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.
Route description
I-405 begins at a three-way stack interchange with I-5 and Harbor Drive on the south side of Downtown Portland near the South Waterfront neighborhood. I-5 continues northeast from the interchange to the Marquam Bridge to East Portland and south towards South Portland, passing under the Ross Island Bridge. I-405 travels northwest along the foothills of the Southwest Hills, traveling around the urban campus of Portland State University and passing the end of the South Park Blocks. It begins a short concurrency with US 26.
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. The below-grade freeway is connected to the neighborhood and the western fringe of downtown by a series of ramps that lead to Salmon and Taylor streets. 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.
I-405 intersects Burnside Street and turns due north as it climbs out of the below-grade trench, running parallel to 15th and 16th avenues. 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. A streetcar maintenance barn and railyard is located under the freeway between Marshall and Overton streets. At the northwest edge of Downtown Portland, I-405 intersects US 30, which continues northwest along a short freeway into the Northwest Industrial Area that was originally intended for the cancelled I-505.
I-405 and US 30 become concurrent as they cross over the Willamette River on the eight-lane Fremont Bridge, a steel tied-arch bridge that carries southbound traffic on its upper deck and northbound traffic below. 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. The northern terminus of I-405 is at a stack interchange with I-5 in the Eliot neighborhood; US 30 continues southeasterly onto I-5 for a short distance before beginning a concurrency with I-84. A set of ramps continue northeast from the interchange to Legacy Emanuel Hospital along the alignment of the cancelled Rose City Freeway.
I-405, also designated as Stadium Freeway No. 61, is the shortest Interstate freeway in the Portland area, at . It has a posted speed limit of because of the short distance between interchanges and high volume of merging traffic. The highway is maintained by the Oregon Department of Transportation (ODOT), who conduct an annual survey of traffic volume that is expressed in terms of annual average daily traffic (AADT), a measure of traffic volume for any average day of the year. The busiest section of I-405 is at Burnside Street, which carried a daily average of 131,400 vehicles in 2018; and the least-trafficked section, at Southwest Broadway, carried 84,400 vehicles. The freeway had an estimated 8 hours of northbound congestion and 11.8 hours of southbound congestion in 2017, with average speeds of for northbound traffic and for southbound traffic during weekday afternoon rush hours. TriMet operates one bus route on I-405, Line 24, which uses the Fremont Bridge as a connection between Slabtown and Legacy Emanuel Hospital.
History
Planning and routing dispute
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. Among these were a network of "thruways" for Portland, including a downtown loop consisting of the Foothills Thruway (later forming I-405) and the East-Side Thruway (later I-5), connected by a northern crossing of the Willamette River. The Foothills Thruway would run along Northwest 24th Avenue and terminate at two intersections with Harbor Drive at the Ross Island Bridge to the south and the new Willamette River bridge to the north. A city study released in June 1955 proposed the construction of several freeways in downtown Portland, including the Sunset Freeway and Stadium Freeway—later combined to form I-405. The northern crossing would use the double-decker Fremont Bridge, which had been proposed earlier as part of U.S. Route 99W in the 1920s but defeated in public referendums.
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. The freeway was estimated to cost $71 million in 1958 dollars (equivalent to $ in dollars) and would be funded primarily by the federal government under the Interstate Highways program. The Oregon Highway Division studied a set of five alternate routes for the freeway, designated as Interstate 405 by the federal government in 1958, with input from the city government over potential impacts to the west side of the central business district. The southern section from the Marquam Bridge to US 26 near Southwest Jefferson Street was split into two options: the Clay–Market route, following Clay and Market streets to the north of Portland State College; and the Foothills route, which would curve along the southwest side of an urban renewal area with a depressed roadway. The northern section from US 26 to the Fremont Bridge was split into three options: an elevated freeway between 15th and 16th avenues proposed by the city; an elevated freeway between 18th and 19th avenues; and a depressed roadway between 21st and 22nd avenues.
The city government, Portland State College, and downtown business groups lobbied in support of the Clay–Market route, producing their own study that claimed it would preserve downtown property values. The Oregon State Highway Commission and Bureau of Public Roads preferred the Foothills route because it had $4 million (equivalent to $ in dollars) in cost savings compared to the Clay–Market route. 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. By late May, a total of 389 households and 37 businesses had been relocated in anticipation of the freeway project, while 47 buildings had been demolished. The state highway commission hosted a public hearing in June 1960 to hear testimony from 300 people at Portland's Public Auditorium. The commission adopted the Foothills route and 15th–16th elevated freeway for I-405 on July 8, which would cost an estimated $75.7 million to construct (equivalent to $ in dollars). The Portland City Council then voted on July 14 to approve the general route endorsed by the state highway commission.
Property acquisition and Foothills construction
The state government began negotiations to acquire property along the Stadium Freeway's future right of way in October 1960, later requesting federal funds to aid the city government with relocating an estimated 1,100 households affected by planned demolitions. An estimated 554 buildings with 1,668 residential units were in the right of way for the freeway, including a school, several churches, and a recently completed synagogue for Congregation Shaarie Torah. 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. The state government agreed to assist in relocating the residents to a new building, but its lack of a fire sprinkler system mandated for recipients of state welfare forced the eviction of 80 residents from the Carlton Hotel. 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. The state highway commission approved the designation of Highway No. 61 for the Stadium Freeway on December 8, 1961.
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". 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. The protests coincided with the growing opposition to other freeway projects in the Portland area, including the Laurelhurst Freeway (I-205), at the onset of the region's freeway revolts. A pair of downtown businessmen formed the Citizens for Sane Freeways Committee and attempted to lobby the Bureau of Public Roads to adopt Harbor Drive as its route for I-405, but they were rejected because it did not meet modern freeway standards. The group later circulated a public petition with 3,000 signatures opposing the construction of the 13th–14th avenues section of the freeway between US 26 and Burnside Street. On March 22, the city council voted unanimously to approve its agreements with the state highway commission after a four-hour public hearing with 35 speakers, allowing the state government to resume property acquisition.