I-5 & Alaskan Way Viaduct

Central Seattle has two major north-south highways in bad need of improvement - the Alaskan Way Viaduct section of State Route 99, on the city's downtown waterfront aside Elliott Bay; and the poorly designed, badly congested stretch of Interstate 5 running from downtown north through the city. Smooth and safe movement of passenger and freight vehicles throughout Puget Sound and the Cascadia Corridor of Oregon, Washington and British Columbia requires that the Viaduct and I-5 be improved in Seattle. Neither is included in the fall roads and transit ballot measure.

Cascadia has introduced the downtown bypass/bored tunnel proposal to replace the Viaduct, plus I-5 tolled reversible lanes as a joint public-private project that would use union pension funds. A deep bored tunnel could provide six lanes, three in each direction, with one dedicated for transit, under Seattle. More importantly, such a deep bored tunnel would not result in disruption to the waterfront, which would not have been the case with the previous cut and cover tunnel proposed by Washington's Department of Transportation. (That tunnel would have closed the waterfront up to two years, for construction of the tunnel as well as the adjacent sea wall.)

Additionally, the price for a deep bored tunnel will be lower. We commissioned a study done by Arup, an international consulting firm, which indicates that a deep bored tunnel to replace the Viaduct could carry six lanes, and cost about $3 billion, a figure which would be less than the $4.6 billion that our state's transportation department estimated it would cost for the cut and cover tunnel on the waterfront. And there is further evidence from around the world that costs can be managed; recently, a 21-mile tunnel under the Alps was built for $3.5 billion.

In our scenario, the deep bored tunnel could be constructed without disruption to the downtown area or the waterfront. All of this could be done while surface transit options are implemented. The result would be a win-win for all stakeholders.

Cascadia Center plans an international forum in late 2007, after the November roads and transit ballot measure, to discuss and review with experts from Europe, North America and Asia how this advanced construction technique could be applied here in Seattle.

"Viaduct Bypass, I-5 Expansion Should Be Linked," Bruce Agnew, Cascadia Center For Regional Development, Puget Sound Business Journal, 8/10/07.

"Bored By All Those Viaduct Choices? Think Again," Glenn R. Pascall, Puget Sound Business Journal, 3/16/07.

"Alaskan Way Replacement: Alternative Approaches," Ove Arup & Partners, 11/06.

State Route 520/Evergreen Point Floating Bridge

The four-lane SR 520/Evergreen Point Floating Bridge is a key link between Seattle and regional centers across Lake Washington such as the growing city of Bellevue, and Redmond, home to the Microsoft Corporation. State officials have made replacement of the bridge a top priority because as currently constructed, it could sink in 70-mile-per-hour winds or an earthquake. Cascadia supports a six-lane replacement with some form of mass transit. Communities at each end are intent on winning strong environmental mitigation measures.

The total costs may well exceed the estimated $4.4 billion. SR 520 tolls will need to be coupled with tolls on the parallel Interstate 90 bridge across Lake Washington in order to generate enough additional revenue to pay for the 520 bridge rebuild, and to prevent overburdening I-90 with toll-avoiding motorists. The U.S. Department of Transportation in August 2007 announced a $138 million Urban Partnerships Program grant for the SR 520 bridge-rebuilding project, conditional on SR 520 tolls being levied.

"New Grant For Bridge Rebuild Prods Regional Tolling Debate," Bruce Agnew, Cascadia Prospectus, 8/15/07

"New 520 Bridge May Mean Tolls On I-90, Too, Chris McGann, Seattle Post-Intelligencer, 4/9/07.

"Report On SR 520 Bridge Replacement And HOV Project Funding Alternatives," Seattle-Northwest Securities Corporation, Montague DeRose & Associates, LLC, 3/28/07.

"Lake Washington Urban Partnership," Washington State Department of Transportation, 4/30/07.

"Report Card For America's Infrastructure," American Society Of Civil Engineers.

Columbia River Crossing Project - Portland, Oregon

Many northwest motorists are familiar with the scenic, dramatic vistas from the Interstate Bridge on I-5 connecting Vancouver, Washington and Portland, Oregon across the mighty Columbia River - a storied passage to the Pacific Ocean. But due to factors including continued growth in Metro Portland, and heavy interstate traffic on I-5, congestion is a serious problem in the bridge corridor. So the transportation departments of both states are teaming with regional officials and stakeholders through the Columbia River Crossing project to choose how to best ease congestion for the future, and improve corridor mobility and road safety.

The Columbia River Crossing Draft Environmental Impact Statement alternatives are: a replacement bridge with either Bus Rapid Transit or light rail; versus a supplemental bridge with either Bus Rapid Transit or light rail. Another option is "no build." A DEIS preferred alternative will be selected and an official public comment period on the selection initiated in Spring, 2008.

Columbia River Crossing Web site.

Columbia River Crossing Project Alternatives Page.