Interstate 405 (Oregon)
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.
Interstate 405 | ||||
|---|---|---|---|---|
| Stadium Freeway No. 61 | ||||
A map of central Portland with I-405 highlighted in red | ||||
| Route information | ||||
| Auxiliary route of I-5 | ||||
| Maintained by ODOT | ||||
| Length | 4.25 mi (6.84 km) | |||
| Existed | 1958–present | |||
| NHS | Entire route | |||
| Major junctions | ||||
| South end | I-5 in Portland | |||
| US 26 in Portland US 30 in Portland | ||||
| North end | I-5 / US 30 in Portland | |||
| Location | ||||
| Country | United States | |||
| State | Oregon | |||
| Counties | Multnomah | |||
| Highway system | ||||
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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 outcry; 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.