Design chosen for Interstate 5 bridge

| Monday, February 28, 2011

State officials in Oregon and Washington have chosen a design for a proposed new Interstate 5 bridge over the Columbia River. They say a deck-truss design would be the most cost-effective and least damaging to the environment of the submitted proposals.

 

An artist’s rendering of the chosen deck-truss design for a new I-5 bridge linking Oregon and Washington state over the Columbia River. Image courtesy of the Columbia River Crossing.

A deck truss with 10 river piers to replace the current bridge over the Columbia River will still cost $340 million, not including land acquisitions and roadway access points in Portland, OR, and Vancouver, WA.

A governor-appointed bistate panel has recommended tolls to help finance the bridge. Tolls would vary during peak and off-peak traffic times.

About a year ago, officials floated the idea of tolling the existing I-5 and existing I-205 bridges to jumpstart the financing. That drew comments from hundreds of motorists and truckers in opposition to the idea. Many motorists and truckers polled during public hearings said they would prefer no toll on the replacement bridge, either.

The Columbia River Crossing continues to accept comments throughout the process. To comment, send an e-mail to feedback@columbiarivercrossing.org.

The original bridge at the site was built in 1917 and a twin was added in 1958. The bridge was tolled back then, but tolls were removed once the project was paid off. The bridge is narrow and is inadequate for the capacity, officials say, so it?s time for a new one.

The deck truss beat out two other designs ? a $390 million cable-stayed bridge and a $430 million tied-arch bridge ? as the preferred design. Aside from cost, officials liked the deck truss for its environmental footprint, the unlikelihood of cost overruns and lowest risk associated with attracting private investors.

In 2008, the federal government dedicated $15 million in funding for the project. Including land acquisition and access ramps, the estimated cost for the Columbia River replacement bridge could reach $4.2 billion.

See related stories:
Panel says tolls ‘essential’ for I-5 bridge
Interstate 5 bridge could be tolled early
I-5 toll bridge project makes federal priority list

Comments