Viaduct updates: “South” timetable, “Central” retrofit review


The clock ticks, Alaskan Way Viaduct traffic rumbles on, and the roar of reminders about looming viaduct change gets increasingly louder. In the past six days, we covered two major meetings with viaduct info that will interest anyone who drives it – first, the public comment meeting for the South End Replacement Project “environmental assessment” (and the comment period’s not over yet, so there’s still time for you to have a say), then the advisory committee briefing on why the semi-short list of Central Waterfront options does not include a retrofit (photo above is from that event). Read on for what you should know about both – including links where you can see the full PowerPoint-type presentations from both events:


That’s what the southern mile of The Viaduct is supposed to look like, five or so years down the road. This section, from Holgate to King, is the one whose future is settled – the big question in The Viaduct’s future remains what the north end of this project will connect to.

Project managers say there’s no need to worry, they’ve designed it to connect to just about anything – though they have connoitered their schedule so that if the Central Waterfront decision is made as scheduled by the end of this year, they can tie up any loose ends.

The South End Replacement Project environmental-assessment public meeting was held open-house style at Madison Middle School, with maps and charts on boards you could inspect at will, asking questions:


The comment period for the environmental assessment is open till August 11, and you can read the entire document here. But for practical purposes of how this is going to affect your driving — we zeroed in on one corner of the room: The latest projections for what will happen when.

Here’s the entire set of 18 “boards.” Toplines:

-Construction will start around June 2009 and last just under four and a half years.

-Construction is broken down into a preliminary phase and five main phases. First, utilities will be relocated. Then the southbound side of the new elevated structure (which is side-by-side, not double decker) will be built over the ensuing two years, along with a major detour route to the east of the current viaduct’s south end. The two years after that will involve construction of the northbound side.

-WSDOT promises that throughout construction, it will maintain “a minimum of two lanes of SR 99 traffic in each
direction during peak traffic hours or provid(e) a detour … full closures of SR 99 (will be allowed) only during nights and weekends.”

When it gets closer, we will provide advance and ongoing information about detours, traffic challenges, road conditions, etc., but for now – the most important thing is to be aware this is on the horizon, along with the city’s Spokane Street Viaduct work (recent WSB in-depth update here), which — along with the South End project — is supposed to be done before the Central Waterfront replacement gets going sometime in 2012.

Again, here’s the link to the full environmental assessment; here’s the 18-page file with the toplines; this page offers two ways to comment – the deadline is August 11.

Now, the retrofit briefing, which was organized for Alaskan Way Viaduct Stakeholder Advisory Committee members (roster here), who were joined by project leaders from the city, county, and state, as well as some other interested observers, and three identified media representatives (including us). One of the West Seattle residents on the committee, Vlad Oustimovitch, requested more information when the options were unveiled last month (WSB coverage here) with the retrofit seemingly abruptly dropped from the list, despite strong voices advocating it, and he was among those on hand for it.

The PDF of this briefing is also available online; see it here.

This wasn’t the last word on the retrofitting idea; project leaders promised the Viaduct Preservation Group – the major advocates for a retrofit – they would meet with the group’s technical consultant to further review their latest proposal. But most of the briefing centered on dissecting everything that had been proposed so far.

A variety of studies going as far back as 1995 were cited; you can find links to those reports, and a summary of them, here.

Project leaders opened by reiterating the four “guiding principles” of the Central Waterfront project that they say would not be met by a retrofit:
-doesn’t improve public safety
-doesn’t enhance Seattle’s waterfront
-not fiscally responsible
-doesn’t improve health of environment

Project leaders had said that a retrofit would cost almost as much as a new structure and would still require long periods of closures; this briefing was about the specifics behind their contentions. The existing viaduct’s columns are big but weak at heart, they said — “steel really gives them strength but there’s not much steel; we call the viaduct under-reinforced in many areas,” said WSDOT’s Ron Paananen. The rebar in the viaduct’s concrete was welded in spots – “that’s considered bad practice these days.”

You’ve heard about the viaduct’s dangers before, and all of them were reiterated here, including the fact that it has what’s considered an 8.99 “sufficiency rating” on a scale of 0-100, per factors laid out by national organizations of experts – anything below 50 should be replaced, experts insist. A state bridge expert said the structure also has too low a “load rating,” which is why you see those signs saying heavy vehicles need to stay in certain lanes: “That shows how close we are to a possible failure mode, just due to normal traffic.”

Another contention: A retrofit would only extend the viaduct’s life another 25 years or so and make it able to withstand a “500-year earthquake”; major bridges are now being built to a “2,500-year earthquake” standard, project leaders said (although it was pointed out that the new 520 bridge will be designed to a 1,000-year-quake standard), and they are built to last at least 75 years.

Specific analysis of the studies was outlined by consultant Andy Taylor (here’s the “executive summary”), with the conclusion including this excerpt:

The existing Alaskan Way Viaduct (including foundations), is in an advanced state of deterioration and is approaching the end of its functional life. The damping retrofit scheme proposed by the Viaduct Preservation Group would cost approximately 80 percent of the cost of replacing the viaduct. Construction of any of the retrofit schemes proposed to date would result in significant and long-term disruptions to traffic both on and around the viaduct. A retrofit approach to improving the Alaskan Way Viaduct is neither technically or fiscally prudent.

“Damping” boils down to building “shock absorbers,” usually fluid-filled. Taylor’s analysis listed several other types of retrofitting technology that had been considered, various reasons why they wouldn’t be optimal, and then this conclusion, which Taylor stressed was the key point: That the viaduct’s “existing foundations will not withstand a 108-year earthquake, with or without improvement.” They barely made it through the 2001 Nisqually earthquake, he noted, saying that if it had been just a little shallower or a little longer, “you would have seen different results.” And another biggie is looming out there somewhere, WSDOT bridge expert Jugesh Kapur reminded everyone — “Seismologists say it’s due now.”

It’s not just the viaduct structure that would be likely to collapse in the next big quake, it was stressed; the Alaskan Way underwater seawall, which is also to be replaced in whatever option is chosen for the Central Waterfront Project, would go too — leading to “a lateral movement of soil” that theoretically could knock down the viaduct’s existing columns.

After establishing the contention that various retrofit options weren’t feasible, Taylor’s analysis moved on to note that “maintenance costs of a retrofit would be higher than with a new structure” – blaming that on everything from “chloride in the concrete” (from the salt air/water) to exposed rebar to the “nonstandard” railings. Then the Viaduct Preservation Group’s claim that a retrofit would require fewer construction closures also was challenged — “A retrofit of any type would involve extensive structural work, so it would be closed for many months or years,” Taylor said, envisioning a “7- or 8-year construction schedule.”

The final section of the briefing looked at the government reps’ cost estimates, comparing a retrofit to a new elevated structure. They say the retrofit would cost $2.268 billion, while the “full elevated replacement” would cost $2.828 billion.

In conclusion, Paananen said it all comes down to whether it’s “a fiscally responsible decision to spend all this money to retrofit the viaduct and only get another 25 years out of it.”

After the official presentation concluded, representatives from the Viaduct Preservation Group were given time, at their request, to make their counter-argument. They think a retrofit could be done with less time and less money than government reps say it would require. Art Skolnik called the viaduct “a resource” and described a retrofit as “a Seattle solution,” saying that the state should spend maybe $30,000-$50,000 to have “(their) people” get a shot at the idea. Victor Gray suggested a retrofit could extend the viaduct’s life beyond the 25 years the government experts say it has left. And as for those who say it’s a good idea to get rid of the viaduct anyway, he countered, “We think the retrofit gives us a new opportunity to look at the viaduct as a unifying opportunity along the water. It was never meant to be a barrier, it was built elevated so (people could move underneath it).” The VPG also believes that resurfacing the viaduct with asphalt could cut the traffic noise in half.

After the VPG presentation, as the meeting concluded, Peter Philips, a stakeholders-committee member from the Seattle Marine Business Coalition, said: “I don’t think the retrofit has been vetted … I still am unconvinced that it should be taken off the table at this time.”

The government reps indicated they’re willing to keep talking about it, but their minds didn’t appear to have been changed either.

WHAT’S NEXT: As mentioned above, comments on the environmental assessment for the South End Replacement Project will be taken through August 11; find the assessment, summary, and how to comment, here. For the Central Waterfront Replacement Project, the Stakeholders’ Advisory Committee meets again this Thursday. A decision on the Central Waterfront plan is supposed to be reached by the end of the year (the scenarios currently under construction, A through H, can be reviewed here). A ton of information about these parts of the viaduct project and others can be accessed at

1 Reply to "Viaduct updates: "South" timetable, "Central" retrofit review"

  • Rick July 22, 2008 (9:24 am)

    Just a bit curious as to where “very bad” falls on the Richter scale?

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