Design Innovation: Two-state solution

Aug. 18, 2009

I-5 is a vital thread of highway, knitting together the three West Coast states, Canada and Mexico. It also is a key transportation corridor for local travel between Portland, Ore., and Vancouver, Wash., two cities separated by the Columbia River.

A unique partnership in transportation planning has taken shape for the Columbia River Crossing project (CRC) involving two states, six local agencies, the federal transit and highway administrations and thousands of engaged community members.

I-5 is a vital thread of highway, knitting together the three West Coast states, Canada and Mexico. It also is a key transportation corridor for local travel between Portland, Ore., and Vancouver, Wash., two cities separated by the Columbia River.

A unique partnership in transportation planning has taken shape for the Columbia River Crossing project (CRC) involving two states, six local agencies, the federal transit and highway administrations and thousands of engaged community members.

CRC is a bridge, transit and highway project aimed at improving travel safety and efficiency on a key stretch of I-5. CRC will build a replacement bridge for I-5 over the Columbia River, improve 5 miles of highway and seven interchanges, extend light-rail transit from Portland to Vancouver and upgrade bike and pedestrian facilities. Over 50 structures on land or over water will be constructed or improved.

A tale of two bridges

In 1905, the first world’s fair to be held in the Pacific Northwest opened in Portland. The event was a promotional boon to the Portland-Vancouver area but caused a massive traffic jam at the Columbia River steam ferry, one of the few passageways between the two cities. The jam sparked widespread demand for a bridge between the two states. In 1914, with local support, the Washington and Oregon state legislatures approved the sale of bonds to fund such a bridge. It was designed as a drawbridge to accommodate river navigation.

The new bridge opened in 1917 amid much fanfare. Travelers paid five cents to cross using two lanes of traffic, one in each direction. A streetcar shared the roadway with Model T Fords. Because the bridge was heavily used, the original bond was paid off within 12 years and tolls were removed.

Today’s Interstate Bridge has two side-by-side spans—the original bridge carrying northbound I-5 travelers and a southbound bridge added in 1958—each with three lanes. To pay off the second construction bond, tolls were again collected—20 cents for cars, 40 cents for light trucks and 60 cents for heavy trucks and buses—until 1966. Once again, CRC plans to help fund the new bridge with tolls. However, this time electronic tolling will be used, and rates could vary based on congestion levels.

The bridge designers of the early 19th century could not have imagined the demands on what is now an interstate bridge. Many problems now exist:

Congestion: The existing bridge carries 135,000 vehicles per day. Because congestion is so heavy in the morning and evening commute hours, bridge lifts for river traffic have been restricted during those times. By 2030, the Portland-Vancouver metropolitan area is expected to grow by 1 million people. Without a new bridge, today’s traffic congestion will increase from four to six hours a day to 15 hours a day.

Impaired freight mobility: The Portland-Vancouver area’s economy is more dependent on transportation and trade than others of its size. Today, freight mobility is impaired on this stretch of I-5, which includes the most important highway interchange for freight in the entire state of Oregon.

Limited transit options: There is no form of high-capacity public transit, such as light rail, across the Columbia River. Bus service gets stuck in traffic despite a special northbound lane for buses and carpools. The bridge project is planning for a multimile extension of Portland’s acclaimed MAX light-rail system from north Portland to Clark College in Vancouver.

High collision rates: Crash rates on this stretch of I-5 are two to three times higher than on similar urban freeways around Washington and Oregon caused in part by closely spaced interchanges and tight merges. Additionally, the Interstate Bridge is the only drawbridge on I-5 between Canada and Mexico. During a bridge lift, motorists are three to four times more likely to be in a crash. A new bridge will eliminate lifts.

Substandard pedestrian/bicycle pathway: Bicyclists and pedestrians use a substandard, narrow path across the river. Bridge sidewalks average 4 ft wide and are located very close to traffic lanes. The connections to the path are confusing and require out-of-direction travel.

Seismic risk: Lastly, the existing bridges are supported by timber pilings driven approximately 70 ft below the river bottom. Recent geotechnical studies have shown that the sandy soil under the bridges will likely liquefy to a depth in excess of 70 ft during a significant earthquake. This could cause severe damage to the bridges. A replacement bridge will be designed to meet current seismic standards.

The interstate bridge has served the region well for more than 90 years, but it is time to replace the two structures to meet the next century’s growing travel needs across the Columbia River. To address the transportation problems on I-5, integrated bridge, public-transit and highway solutions are needed.

Important’s top 3

Regional and local elected officials and business and community leaders have been working together for more than a decade to study the problems on I-5 and create solutions. In 2002 the CRC project area was named as one of three important projects for I-5. By 2005, the environmental review process began and a 39-member bi-state task force was appointed to advise the departments of transportation about scope, alternatives development and preferred alternative. In mid-2008, after the project’s draft environmental impact statement was produced, six local partner agencies (cities of Portland and Vancouver, two transit agencies and two regional planning organizations) agreed on a locally preferred alternative. Key elements include a replacement bridge for I-5 and the extension of light rail from Portland to Vancouver. This option was chosen after reviewing environmental and technical analysis and thousands of public comments. The preferred alternative demonstrates regional consensus and has allowed the CRC project to focus on refining the project’s design during 2009.

As the technical teams continue their work, multiple advisory groups provide input on urban design and aesthetics; freight mobility; interchange design; community and environmental justice; pedestrian and bicycle elements; and transit design. The project has committed to extensive public involvement throughout the planning process, with more than 18,000 in-person conversations and discussions at more than 600 events to date.

Huge benefits package

Numerous decisions will be made this year, including interchange area management plans, the type and design of the new bridge, a financing and tolling plan, selection of light-rail alignment and station locations, location and specifics of the pedestrian and bicycle path and development of a sustainability plan. In all of these areas, CRC is committed to strengthening partnerships and creating a project that works for commuters, the environment, freight, the economy, adjacent communities and local residents.

With the support of Oregon’s and Washington’s governors, CRC is confident it can design and implement a project that benefits the environment and the regional economy. The project recently won a national award for the inclusion of greenhouse-gas analysis in the environmental review process, and an independent review panel has confirmed the methodology and analysis. Using an energy-consumption-based model, CRC found that the highway improvements would lead to an estimated 9.5% decrease in greenhouse-gas emissions compared with the no-build alternative. Refinements are now being made to the analysis to include all elements of the project.

CRC also will provide significant benefits to the local and regional economy. A near-term benefit includes 27,000 jobs that will be created or sustained by construction. Longer term, the congestion relief provided by the replacement bridge, tolling, interchange improvements and transit will let goods and services move more efficiently. By 2030, about 20% of the traffic in the project area will be freight.

Producing a project that benefits current and future populations is a key tenet of sustainability. CRC is documenting how it will integrate sustainability principles into all phases of the project, from planning to design to implementation. It is a collaborative process with all partner agencies and considers environmental, economic and community/social opportunities for the project.

The CRC engineering and design teams are viewing constraints with an optimistic lens. There is commitment to building a signature, aesthetically pleasing river crossing that fits with the communities on both sides of the Columbia River, provides sufficient clearance for marine traffic and does not interfere with the airspace of Portland International Airport or Pearson Field, a small regional airport.

Shooting for two

Designers are working to minimize the number of piers in the Columbia River. Segmental concrete, steel box girder, steel I-girder, steel truss and extradosed bridge types are being considered at this time. Cable-stay and suspension bridges have been ruled out because of their height and geometric restrictions.

The new bridges across the Columbia River were initially conceived as a three-structure design—with northbound highway traffic on one bridge, southbound on a second bridge and light rail on a third bridge, alongside a bicycle and pedestrian path. However, after conducting a value engineering review, the project team crafted a two-structure alternative with a smaller environmental and visual footprint. Northbound and southbound highway traffic would be on separate structures. Light rail could travel below the southbound deck and the bicycle/pedestrian path could be below the northbound deck. This innovative two-bridge design is endorsed by the project’s Urban Design Advisory Group and recently was endorsed by the project’s sponsors council of elected officials and transportation department directors.

The project’s estimated construction cost is $3.1 billion to $4.2 billion (in year-of-expenditure dollars). The finance plan will be refined in 2009 and will include updated cost estimates. Funding is expected from a variety of sources including federal, state and local budgets and tolling.

The project assumes the toll amount would vary by time of day with the highest tolls paid during the most congested time periods. Drivers who travel outside peak hours would pay a lower toll. A variety of scenarios will be studied and reviewed with the public before toll policies and rates are established.

In 2010, the CRC team expects to release its final environmental impact statement and a federal decision on the project. In 2011, any necessary right-of-way and property acquisition would begin while final designs are wrapped up. The soonest construction could begin is in 2012 with construction lasting anywhere from five to seven years, depending how it is contracted.

About The Author: Columbia River Crossing project team acknowledgments:

Richard Brandman, Oregon DOT director
Doug Ficco, P.E., Washington State DOT director
Ron Anderson, P.E., David Evans & Associates Inc., Columbia River Crossing project man

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