CogKnoSys

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Physical

I-5 Interstate Bridge

The Interstate Bridge is a pair of steel lift bridges carrying Interstate 5 over the Columbia River between Vancouver and Portland.

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↓ Specific: nothing more specific yet

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The idea

The Interstate Bridge is a pair of nearly identical steel bridges that carry Interstate 5 over the Columbia River between Vancouver, Washington, and Portland, Oregon. It is also called the I-5 Bridge or the Columbia River Interstate Bridge. Each bridge is a vertical-lift, Parker through-truss design, so part of the deck can be raised straight up to let tall ships pass.

Its name simply described a bridge linking two states, decades before the Interstate Highway System existed. Each bridge is over 3,500 feet long with three lanes, and in 2006 the two carried 130,000 vehicles a day. The bridge was added to the National Register of Historic Places in 1982.

The bridge is blamed for traffic jams on both the highway and the river, and it does not meet current seismic standards. Plans to replace it have been debated since 2005. A replacement plan called the Columbia River Crossing was canceled in 2013 after the Washington state legislature declined to fund it. A joint Oregon–Washington legislative committee restarted the work in 2017, and the Interstate Bridge Replacement Program was relaunched in 2019.

Check yourself

Question 1 of 3

In what year did the southbound bridge open?

Pick one. The first pick counts.

Composition

what it's made of

  • Northbound span — The original bridge, opened in 1917, which now carries northbound traffic.
  • Southbound span — The twin bridge, opened in 1958 for southbound traffic.
  • Vertical-lift sections — Sections of deck that rise straight up to let tall river traffic pass.
  • Steel trusses — The Parker through-truss frames that hold up each bridge.
  • Traffic lanes — Three lanes on each bridge; in 2006 the six lanes carried 130,000 vehicles a day.

Connection

how it relates

Under Lower Columbia Bridges and Transportation

In place

  1. Columbia Riverstrength 90 of 100

    The bridge carries Interstate 5 over the Columbia River.

  2. Vancouver, Washingtonstrength 80 of 100

    The bridge's northern end is in Vancouver, Washington.

  3. Portland, Oregonstrength 80 of 100

    The bridge's southern end is in Portland, Oregon.

Related

  1. Metals and Alloysstrength 40 of 100

    Both bridges are made of steel, an alloy of iron and carbon.

Change

how and why it evolves

Past
The 1917 bridge first carried two-way traffic on its own, and it became the northbound span when the twin bridge opened in 1958.
Now
A preferred design for a replacement was released in 2022, and its environmental impact statement has since been approved.
Next
In August 2026 the program asked firms to submit their qualifications, a step that may lead to construction of a new crossing in the coming years.

Knowledge you can walk. Read the idea, then step up, across or down.

I-5 Interstate Bridge

The Interstate Bridge is a pair of steel lift bridges carrying Interstate 5 over the Columbia River between Vancouver and Portland.

See it on the map

Learn, discuss, create, buy or invest

The idea

The Interstate Bridge is a pair of nearly identical steel bridges that carry Interstate 5 over the Columbia River between Vancouver, Washington, and Portland, Oregon. It is also called the I-5 Bridge or the Columbia River Interstate Bridge. Each bridge is a vertical-lift, Parker through-truss design, so part of the deck can be raised straight up to let tall ships pass.

Its name simply described a bridge linking two states, decades before the Interstate Highway System existed. Each bridge is over 3,500 feet long with three lanes, and in 2006 the two carried 130,000 vehicles a day. The bridge was added to the National Register of Historic Places in 1982.

The bridge is blamed for traffic jams on both the highway and the river, and it does not meet current seismic standards. Plans to replace it have been debated since 2005. A replacement plan called the Columbia River Crossing was canceled in 2013 after the Washington state legislature declined to fund it. A joint Oregon–Washington legislative committee restarted the work in 2017, and the Interstate Bridge Replacement Program was relaunched in 2019.

Check yourself

3 quick questions, instant feedback.