Interstate Bridge

The Interstate Bridge (also Columbia River Interstate Bridge, I-5 Bridge, Portland-Vancouver Interstate Bridge, Vancouver-Portland Bridge) is a pair of nearly identical steel vertical-lift, through-truss bridges that carry Interstate 5 traffic over the Columbia River between Vancouver, Washington, and Portland, Oregon, in the United States.

The bridge opened to traffic in 1917 as a single bridge carrying two-way traffic. A second, twin bridge opened in 1958 with each bridge carrying one-way traffic. The original 1917 structure is the northbound bridge. As of 2006, the bridge pair handles around 130,000 vehicles daily. The green structure, which is over 3,500 feet (1,067 m) long, carries traffic over three northbound lanes and three southbound lanes. It was added to the National Register of Historic Places in 1982, as the "Portland–Vancouver Highway Bridge".

Since 2005, proposals for replacing the bridge have been produced and debated. The bridge is considered responsible for traffic congestion of road vehicles and river traffic. Height changes may affect two nearby airports. Changes to the river channel may affect a nearby railroad bridge. If a replacement decision is made, construction would commence no sooner than 2013, take five to seven years, and cost in excess of $4 billion, including changes to affected roadways. Delays are due to questions about potential environmental impacts of construction and the completed bridge, Vancouver and Clark County politics, potential for urban sprawl, and uncertainty whether to include light rail and bus lanes.