Hey Ron,

How's this:

Have WSDOT employees sign a contract with the Legislature and the City of Seattle, which pledges all salaries, benefits and personal holdings (such as homes & businesses), retirement funding and savings for their children's education as the way to pay for any and all cost overruns for the
Viaduct replacement Tunnel. Oh, and add to that any economic impacts caused by the project.

That's putting your money where your mouth is, since your department is assuring all of us that there will not be any cost overruns.

Art

uh sure 'arties', and I imagine such a contract would accrue all the benefits from the tunnel project (efficiency gains, regional prosperity - you know the drill) to those same funds (salaries, benefits, savings,etc) that you call out...

By the way, since it appears you're not keeping up, WSDOT's role is to IMPLEMENT the plan - the decision to proceed was ours, represented by our public officials. That means we take the risk, and get the benefit, of the project.

Oh, sorry, it appears you're the type who would dump anything difficult in someone else's lap.

Mr. Paananen, it might help people like Art to get a thumbnail sketch of the risks. What major risks did you start with that are now mitigated, and how? What risks you still have and what mitigation strategy is identified that is intended to prevent the risk from becoming an issue (that's a cost that happened, Art)?
What new risks were identified by your group vs the outside folks consulting.

I know you can not cram everything into an article, but this might help people see finer information that make up the new, and lower, risk cost.

At some point that risk turns into an issue and consumes that estimate in the firm of an issue, or the risk did not happen (or was mitigated) giving us savings.
I know you know all this, but based on some media reports, and comments, I don't think this is broadly understood.

Why did WSDOT continue to study 'Tunnelite' a year and a half after its rejection by voters in March 2007, producing Scenario 'G' 4-lane Cut-n-cover in late 2008? Does WSDOT believe it's a viable tunnel option? If not, why waste time and money in the study?

WSDOT and SDOT have not informed the public 'why' they rejected Tunnelite. Nor have they informed the public of its numerous and critically important advantages. They report only its disadvantage of construction disruption with absolutely no details. The construction process seems manageable, especially when construction disruption is pretty much unavoidable for removing the AWV and rebuilding the seawall and Alaskan Way.

The 40% thru-traffic that the Deep-bore won't accommodate (40,000 additional vehicles daily or 2500 an hour) will create bumper-to-bumper gridlock on the new Alaskan Way. Is 4-lanes is sufficient? I don't think so. And, the "Mercer West" project is a terrible for Lower Queen Anne and will make the Mercer Mess worse. Crunican is gone. Is Paananen next to go?

I continue to love the tunnel. Even more now that the budget seems to be affirmed with a lot more design and testing done.

Wells, since peak sections of Aurora handle 82,000 vehicles per day (with stoplights), the projected traffic on Alaskan Way doesn't sound like too much. As for "tunnel lite", it's worth studying lots of options to a point (and it's correct leadership), but several years of massive disruption make it a seriously flawed idea, better than putting all 100,000 trips on the surface and better than aerial, but a nightmare compared to the deep bore.

The problem with the proposed stoplights on the new Alaskan Way, mhays, is their number: every intersection between Pike and King, 13 stoplights there and 4 stoplight intersections in Lower Belltown and 4 or 5 stoplights south of King Street. Cross traffic from Western Ave and Coleman Dock adds to congestion. In order for the 'additional' 40,000 vehicles of 'thru-traffic' to get through, they'll face stoplight after stoplight of side traffic. At that point, 4 traffic lanes may not be enough to handle predictable bumper-to-bumper back-ups along Alaskan Way.

The AWV remains in place for the 4-lane cut/cover. Once completed, traffic is diverted off the AWV into the new tunnel and onto the stretch of Alaskan Way north of the Pike Street portal while the AWV is removed, the lower Belltown segment and Alaskan Way rebuilt. It's messy, but no nightmare.

I hate the Deep-bore tunnel with a passion. It's a fiasco. Its north portal at Denny/6th has a terrible impact. The Mercer West Project is a shame. It's literally designed to make traffic worse everywhere. Yet, you fall for SDOT's BS propaganda. Seattle traffic is terrible and the Deep-bore makes it worse.

1) If the current viaduct is so dangerous, why pursue the only plan that will keep it in place for 10 more years? What happened to the governor's pledge to have it torn down by 2012?

2) Also, where did these traffic numbers and percentage of "through-traffic" come from and why do you think they will stay the same? Those numbers are for the current viaduct that serves Ballard and has downtown exits and on ramps. The deep bore tunnel does neither. Also, If there is a $5 toll on that tunnel the numbers of users goes way down.

3) What is the percentage of SOV traffic on the current viaduct? What happens when gas prices go through the roof? So called "demand" will go way down.

4) Everyone I know that uses the viaduct for commuting would much prefer to ride a train to work. A train from west seattle to ballard would be much cheaper and cost effective.

5) A tunnel of this kind has never been built--anywhere in the world. Look at the diameter of that this. How much of the design is done? 1% 2% ? It is truly a faith-based design from the discovery institute at this point.

Wells, those stoplights can be synchronized easily since few streets cross Alaskan Way. Regarding the c-n-c tunnel idea, the viaduct would have to be gone to make it work, not only due to the width of Alaskan Way but also because they'd need the ROW up the hill to Battery.

Andy, nobody mainstream is predicting that sort of traffic reduction even with peak oil. If oil use for US driving falls by even 2% per year, it's easy to imagine MPG improvements accommodating much of the drop, and population growth offsetting the rest.

Of course rail should be greatly improved. But that will address the non-tunnel traffic heading Downtown more than it will address the standard Greenwood to Burien commuter or truck.

As for tunnels of this kind, you have to gerrymander a tight description to make that case. Many deep bore tunnels exist in similar soils. Locally we have a much wider tunnel under Mt. Baker. We have a deep tunnel through Downtown that's lasted for many decades, the BN tunnel. Further, while viaducts fall down all the time (Kyoto, LA, SF, etc.), when's the last time a tunnel did the same?

Regarding design, they're much farther along than that. Since the tunnel is farther along in design than the purely conceptual thinking on the other options, it's safe to say the tunnel is the least variable in terms of cost right now.

(That's about construction cost. If you want to measure "unintended consequences, it's hard to approach the construction impacts of the other options, or the permanent impacts of the surface option dumping tens of thousands of additional cars on the streets and turning Downtown into a collection of "Western Ave in Belltown" highways.

PS, why did you say 10 years? The viaduct would be down in 5 or 6. It's being temporarily stabilized and managed conservatively in the meantime to avoid risk.

mhays, listen: All streets from Pike to King 'intersect' Alaskan Way. This side street traffic may not 'cross' Alaskan Way, but it must 'access' Alaskan Way in both directions. Duh. Some stoplight synchronization will occur, but not perfectly as you imagine. Imagine bumper-to-bumper gridlock. Imagine motorists looking to park and being forced to enter backed-up thru-traffic on the new Alaskan Way. This factor alone makes the case for the 4-lane cut/cover tunnel, but there are many other reasons why the cut/cover is the better choice. You've got to think about all this.

The Cut-n-cover tunnel is built (almost) entirely with the AWV in place. Once completed to the Pike Street 'portal', SR99 traffic (from the north) is diverted via Broad Street to the north segment of Alaskan Way and enters the cut/cover tunnel at Pike Street (for a year or so) while building the Lower Belltown segment of SR99, removing the AWV and finishing Alaskan Way.

The proposed Deep-bore tunnel has the largest diameter ever attempted at 54', much larger than the BNSF tunnel. It will pass under the BNSF tunnel at about Pike Street and the elevation from there to the portal at Harrison will be quite steep. It's risky in many ways.

The cut/cover tunnel, on the other hand, is all soft soils requiring standard excavation techniques built in 2-block segments from the south end. Normal Alaskan Way traffic is diverted around the trench, under the AWV, and returned to the surface above completed segments. Excavation debris is removed to the south via the tunnel. The seawall is rebuilt at the same time. In the end, it creates the strongest seawall and the most stable Alaskan Way surface. It would probably cost less and would certainly create many hundreds more construction jobs.

Pike and Union don't intersect Alaskan, except for driveways. Several streets intersect to the east but only one does to the west, and even the east connections won't be terribly worrisome compared to other routes all over town with major streets crossing them.

Your cut-n-cover plan is mystifying. For example, you'd clearly have to build a bridge over the tracks at Broad to make it even half sensible, and ignore the fact that you'd be routing most of 99's traffic across several major avenues like Elliott, Western, First, Second, etc., and would need a temporary interchange at Aurora somewhere, to say nothing of your one-year north section duration.

Meanwhile you'd be building a tunnel where Alaskan Way is currently. You'd have to shut down pretty much everything for a long time, or add massively to the complexity, duration, and cost of the project by attempting to build while keeping a lane or so open.

With the deep bore, from Pike to Harrison would be what, 100' elevation gain? In one mile? Doesn't sound steep to me.

By "one to the west" I mean the ferry terminal. They actually have two exits. They could presumably switch to one pretty easily though, and they plan to rebuild the terminal at some point either way.

mhays, WSDOT Scenarios 'B' and 'C' surface boulevards show stoplights at Pike and Union. The Deep-bore increases traffic on Alaskan Way by about 40,000 vehicles daily or 2500 per hour, give or take depending on time of day. That's a lot of traffic running 13 closely-spaced stoplights with side traffic. SDOT and WSDOT expect gridlock all day long and don't care.

Pike and Harrison are about a mile apart, 5200'. The difference in elevation is about 200'. The steepest grade occurs over a central 2000' segment.

The AWV remains in place during construction of the cut/cover tunnel. A bridge over the railroad tracks at Broad Street was recently determined as part of all plans. Diverted Aurora-bound traffic uses Broad Street straight to Aurora and Republican Street. Ballard-bound traffic already uses Elliott and Western so diversion across the bridge onto 'north' Alaskan Way and into the completed cut/cover north portal is not too bad.

Normal Alaskan Way traffic is diverted around the trench, under the AWV, and returned to surface above completed segments of the cut/cover tunnel. Excavation debris is removed via the tunnel to the south. The seawall is rebuilt at the same time. What's so mysterious?

Do you know why SDOT/WSDOT moved the Deep-bore north portal from Aurora to 6th Ave? They say it's to reduce impacts and costs. Not true. You tell me, why was the portal moved to 6th Ave? Sometime, I'll lay out a better plan for the new Alaskan Way that was produce by WSDOT in 2001. You can critique it too if you want.

Harrison & Aurora is about 70' above sea level if I recall. It's an easy grade even for a freeway. Even at 200' it would be very reasonable.

I was forgetting the opportunity to divert AW traffic under the viaduct.

Still, I'm not buying your plan at all. It's oozing with cost risk, disruption to neighbors, and gridlock during construction, and your schedule assumptions don't seem realistic at all (one year for the north segment?).

There's no reason why improved surface Alaskan Way should have any more stoplights than it has now, unless the purpose is just to be meanspirited.

I suspect the folks who don't want that option simply put them in, without evaluation, knowing it helps make that option unattractive.

R on Beacon Hill, The existing Alaskan Way layout has a frontage road/parking lot which allows side traffic to avoid Alaskan Way. Without the frontage road, there must be stoplights at every intersection. Early WSDOT designs (pre-Crunican) included a frontage road which allows at least 3 of the 13 stoplights between Pike and King on new Alaskan Way to be eliminated.

mhays, take your pick: traffic hassles a few years constructing the cut/cover, or, traffic hassles forever with the Deep-bore. Be penny-wise, pound foolish if you want. You'll regret it later.

http://www.wsdot.wa.gov/NR/rdonlyres/83C1AAF1-67DB-49A1-95E5-6AE65F1DF87C/0/North_Portal_Proposed_Design_11_30_09.pdf

Here's a link to WSDOT's latest revised Deep-bore north portal design, mhays. You figure out why they moved the portal to 6th Ave.

Yes, I've seen that.

WSDOT's reasoning makes sense -- they're moving it to 6th to avoid construction conflicts with the existing Aurora. Those would otherwise include logistical challenges for construction that would greatly add to the cost and schedule, as well as much more potential for inconvenience to traffic on Aurora.

In fact, it looks like a very stark advantage to use 6th. Cheaper, quicker, fewer variables, less potential for inconvenience...

WSDOT's code for 'construction impacts' is 'inconvenience to motorists'. I won't disagree that 6th is the better choice in that regard, but the bigger problem remains: the Deep-bore worsens traffic on Mercer and on the new Alaskan Way, and thru-traffic is inconvenienced.

The Deep-bore inconveniences motorists indefinitely. Thru-traffic that once directly accessed SR99 at Western/Elliott are routed indirectly up steep 2-lane Mercer Place through Queen Anne, or, over the railroad tracks at Broad Street, or, through Lower Belltown, then Alaskan Way and 20-some stoplights with bumper-to-bumper traffic. The Deep-bore also harms pedestrian environments along Seattle's waterfront and along Mercer through Queen Anne. It's nothing to be proud of and it pisses me off.

Civil Engineer Paananan's WSDOT is about to erect a double-decker SR 520 bridge over Lake Washington that looks mighty like the Viaduct, except that with noise walls atop, it's even uglier. What progress--from our waterfront to our inland bays and lake.
Erin O'Connor

It looks to me like the people in this thread have some working knowledge of the issue. To clarify, tunnels of similar size have been built before, and with great success. The roadway tunnel in Shanghai was over 50ft diameter excavated right next to the river, and the Port of Miami tunnel, which is going into construction shortly is over 40ft in diameter going under the ocean. The Tunnel Option is feasible and constructible.