Rebuilt version of viaduct would be 50 percent wider, drawings suggest

What would the waterfront look like if we scrap the mayor's costly tunnel and build a new Alaskan Way Viaduct above ground?

The new highway would need to be 50 percent wider than the existing structure, according to recent design drawings.

A "rebuild" option gained momentum last week as lawmakers realized that Seattle Mayor Greg Nickels doesn't have the estimated $3.6 billion needed for a tunnel.

A House committee passed an amendment setting an April 1 funding deadline — in effect, mandating a cheaper overhead highway for $2.5 billion. Then the House eased the deadline to Jan. 1, allowing the mayor nine more months to line up funds.

But as a possible backlash against the tunnel emerges, the large size of the rebuild alternative hasn't become common knowledge yet.

Asked about size last week, Reps. Helen Sommers and Mary Lou Dickerson, both anti-tunnel Democrats from North Seattle, thought a new aerial highway would leave the same footprint as the 1952 version. Rep. Ed Murray, D-Seattle, a tunnel supporter and House Transportation Committee chairman, knew the rebuild would be bigger. Sen. Mary Margaret Haugen, D-Camano Island, chairwoman of the Senate Transportation Committee, had no idea.

"It certainly couldn't be any uglier," she said.

Some confusion is understandable.

Two years ago, an environmental-impact statement said "the rebuilt viaduct would have almost the same dimensions and alignment as the existing viaduct, so the look and feel of the corridor would be similar to existing conditions. However, columns would be farther apart and more slender."

Since then, further studies by the Washington State Department of Transportation point to a 75-foot-wide highway instead of the 50 feet we have now.

• Columns would be 8-foot-wide cylinders, to withstand the worst expected earthquake in 2,500 years, project manager Ron Paananen said. The current viaduct has 4-foot-by-5-foot rectangular supports.

• New shoulders would allow cars to pull off the highway, which is impossible now — as seen on Friday morning, when a truck had a flat near Pioneer Square and slowed morning traffic.

• Traffic lanes would be 12 feet wide. On the current viaduct, some are 10 feet or leaner, so trucks and buses can't fit into them.

After she confirmed the Transportation Department's figures, Dickerson said more space for safety shoulders "seems to be a reasonable approach and does not change my position in support of the rebuild."

To imagine the additional viaduct width, visualize the concrete extending toward the waterfront and over the bike lane on Alaskan Way, with columns planted where the streetcar track is now.

"The aerial structure itself is absolutely not an acceptable option," said Sally Bagshaw, chairwoman of the Allied Arts waterfront committee, who compared it to the Westside Highway in New York City. "It will kill the waterfront for the next 75 years."

Another group, the People's Waterfront Coalition, advocates removing the highway altogether; residents would rely more on transit.

Computer images of the wider viaduct will be released this summer, and Deputy Mayor Tim Ceis plans to use them in pro-tunnel lobbying.

"I think there is not an understanding by the Legislature — or I think the public, necessarily — that what's euphemistically called a 'rebuild' is a brand-new aerial freeway that's significantly larger than the one that's there today," he said.

The tunneling option also includes elevated sections at each end of the one-mile underground portion, as well as a 7 percent slope approaching the Battery Street Tunnel.

Tunnels have a history of cost overruns, and even if the state's $3.6 billion cost estimate holds up, there isn't enough cash unless the City Council provides a proposed $550 million, some of which would show up as higher utility bills. The Port of Seattle is being asked for $200 million, and some toll income would be used.

City Councilman David Della, who criticized the tunnel in December, said the increasing size wouldn't change his mind.

"The bottom line is, we need to do what we have the money to do," he said.

Mike Lindblom: 206-515-5631 or mlindblom@seattletimes.com