A tunnel to keep the traffic moving, a new welcome mat for Seattle's front door

On Feb. 28, 2001, in the middle of a peaceful workday, the Nisqually earthquake shook our region from Centralia to Carnation. Although no one was hurt, thankfully, the quake severely damaged the Alaskan Way Viaduct, or State Route 99.

The viaduct is one of the state's most important transportation corridors, carrying 110,000 vehicles a day. Since the quake, we've spent millions of dollars to patch and secure it, but no amount of patching can change the fact that the viaduct is a dying structure. Its concrete is crumbling. Its steel shows signs of decay. It rests on fill. Since the Nisqually earthquake, it has moved two more times.

The nearby seawall is also at risk. Its support timbers have been eroded by decay and infestation by underwater wood lice, called gribbles, and the structure was damaged in the earthquake.

Both it and the viaduct are vulnerable to the next earthquake, and the failure of one could cause failure of the other. In the face of this threat to public safety and to the economy, we must replace the viaduct and seawall. This is a 100-year opportunity to improve traffic and recreate our waterfront.

After two years of analysis and public involvement, the city, the state Department of Transportation and the Federal Highway Administration will jointly hold a news conference to announce tomorrow that a six-lane tunnel is the preferred option for the Alaskan Way Viaduct and Seawall Project.

Building another double-decker freeway on Seattle's waterfront is not the right choice for Seattle or the region. Instead, we should build a tunnel that moves cars and noise off our waterfront, while maintaining our 21st century transportation network.

A lot of thought and discussion brought us to this point. We held more than 250 meetings and received 4,500 comments from the public.

Two central themes emerged.

First, people worried about their ability to get into and through downtown. Seattle is famous for its traffic congestion, and no one wanted it to be worse. We had to maintain connections for westside neighborhoods like West Seattle and Ballard. And we had to maintain capacity for freight and people. We had to keep Seattle moving.

Second, people realize that the waterfront is a public asset — a destination for residents of Seattle and the region. Public waterfront is precious, and we should do everything we can to make it cleaner, less noisy, less harmful to our environment, and make it more accessible and more enjoyable for all.

We also took into account the evolution of the central waterfront. That part of the waterfront used to be Seattle's industrial "back door," but the ships and cranes have moved south, and it's no longer just a working waterfront. Our central city is becoming a place to live, as well as work, and the viaduct replacement choice should reflect the fact that the central waterfront is now our front door. We should recognize that the waterfront is a place for people to wander, meet friends and family, and enjoy the views of the city and Puget Sound.

We studied five alternatives, all of which involved replacement of the seawall, and two options emerged as front runners:

Rebuild the viaduct. This option is basically a recreation of the structure we know today; it's of similar size, but with a safer support system. Cost: $2.7 billion-$3.1 billion.

Build a tunnel. This option is a cut-and-cover project that creates a tunnel to carry traffic. Coming from the south, the road would dip below ground at South Dearborn Street and rise near Pike Street to connect with the existing Battery Street tunnel. Cost: $3.4 billion-$4.1 billion.

Both structures preserve neighborhood connections from White Center to Crown Hill, access ramps at Western and Elliott avenues, and our capacity to move people and freight into and through the city. Only the tunnel creates a new regional destination for all.

We recognize that with a project so large and complex, there may be complications from design, costs and financing. For that reason, the rebuild option will be carried forward as a contingency during the next stage of analysis.

The tunnel is our strong choice as the preferred alternative because of its overwhelming public benefits.

Imagine our waterfront without the noise, blight and dirt from a nearby elevated freeway. Imagine walking along the waterfront and actually hearing the words of the person next to you, or hearing the cry of a seagull and the splash of the waves instead of rush hour.

Imagine a walk from Pioneer Square, along the water, and up to Seattle Center. Imagine a lid that extends Victor Steinbrueck Park and creates a new pathway from the Pike Place Market down to the waterfront. Imagine walking down University Street and down Harbor Steps toward a view of the Olympic Mountains: Compare that to today's experience of walking into shadow cast by a freeway.

The tunnel creates a new waterfront as a place for street-level shops; it affords improved access to the streetcar; and it opens up a great entry for the aquarium, concerts and many other attractions. It creates an interesting streetscape for merchants, pedestrians, joggers, bicyclists, neighborhood residents, and visitors from the city and the region.

A waterfront for all.

The public already has the greatest stake in this issue because the public is the largest property owner. We have the Seattle Aquarium, Waterfront Park, the Bell Harbor Conference Center and other facilities, and we need to make the most of them.

Very little, if any, land would be developed for private interests by the tunnel. There won't be any new condos or office buildings on this land. Land created by removing the viaduct will enhance the right of way for local trucks and cars, the trolley, public transit, bikes, pedestrian pathways, and expanded public open spaces.

There is no question that the tunnel is a very expensive project, but the tunnel has the best chance of attracting a broad coalition of supporters from business, labor, environmental and community leaders.

We will continue to benefit from the leadership of Sen. Patty Murray and state Rep. Ed Murray, chairman of the House Transportation Committee. Both have been strong advocates for viaduct replacement funding.

The tunnel gives Seattle and the region a well-planned traffic corridor and a usable, friendly waterfront.

The Alaskan Way Tunnel allows us to replace the seawall and the viaduct at the same time, it maintains traffic capacity, and it turns our waterfront, with its amazing views and amenities, into a wonderful regional destination. The waterfront will be our front porch, instead of our back porch.

A waterfront for all.

It's a big job. Let's get started.

Greg Nickels is mayor of Seattle.