U.S. Route 30 in Oregon

Sections of the highway between The Dalles and Ontario generally follow the route of the Oregon Trail, which was used in the 19th century by American settlers to reach the Willamette Valley.[2] US 30 was created as part of the initial United States Numbered Highway System adopted by the American Association of State Highway Officials on November 11, 1926. The number was assigned in place of US 20, which had originally been planned for the corridor in Oregon, after objections from the state government.[3] The new national highway incorporated portions of existing state roads, including the Columbia River Highway, which was constructed between 1913 and 1922 through the Columbia River Gorge.[4][5]

Before the Banfield Expressway was built, the Portland section of US 30 ran on St Helens Road to the Willamette Heights section of Portland, then on Wardway Street, then Vaughn Street, then NW 18th & 19th Avenues, then Burnside Street, and then Sandy Boulevard towards Troutdale. Several sections of the old highway use brown road markers with "Historic US 30" that were installed in the 21st century.[6] The Interstate Highway System, approved by the federal government in 1956, included construction of a freeway in Oregon along the US 30 corridor between Portland and Ontario; it was later numbered I-80N (now I-84).[7][8] The Oregon state government unsuccessfully proposed an extension to cover the rest of US 30 between Astoria and Portland in the 1950s and 1960s,[9][10] which was two lanes wide and in need of funding for improvements.[11][12]

The 104-mile (167 km) Astoria–Portland section had been rebuilt with fewer curves by the 1960s, but remained congested due to its use as a tourist route as well as a bypass of US 99 (and I-5) upon the removal of tolls from the Lewis and Clark Bridge near Longview, Washington.[10][11] In 1969, the state government announced plans to widen the highway between Burlington and the Columbia County border, but declined to fund further projects in favor of improvements in the Portland area.[13] The state later withdrew its proposals to upgrade the entire section to an expressway, stating that US 30 was meant to serve local traffic and could be improved to a four-lane highway instead.[14] A project to widen US 30 near Scappoose and Warren in the 1970s was delayed by a decade due to disagreements between the state and local governments over its routing and an attempt to build a full bypass.[15] The highway remained slightly more accident-prone than others in Oregon; from 1987 to 1992, a total of 22 crashes on 50 miles (80 km) of US 30 in Columbia County resulted in 26 deaths and 769 injuries.[16]

In 1988, US 30 was realigned along NW Yeon Avenue in Portland to alleviate residential congestion.[17] The new route utilized an interchange with I-405 that was intended for a proposed I-505.[18] The proposed Interstate was intended to be a 3.17-mile (5.10 km) freeway spur in northwest Portland that would have connected I-405 to St. Helens Road, the latter being the original route for US 30. Funding for the freeway was withdrawn by the city government in November 1978, as it would have required condemnation and rerouting streets on a swath of land through the Northwest Industrial neighborhood.[19] The federal government formally approved the project's cancellation in December 1979 and reallocated funds to other transportation improvements in the area.[20][21]

In the 2010s, the city of Scappoose proposed the construction of a bypass to carry US 30 around the city.[22] A similar proposal was defeated in 1971 following protests from residents over its disruption to future potential development. The $5.5 million allocation for the bypass project was redistributed by the state to improve other sections of US 30 in Columbia County.[23]

• U.S. Route 630
• U.S. Route 730
• U.S. Route 830