Fewer downtown exits should mean better flow through SR99 because there will be less intra-city traffic clogging lanes. That's one of the reasons the Big Dig improved traffic on I-93, they removed a bunch of downtown and South End exits. Of course the Big Dig supplemented that by increasing the capacity of surface streets on and around Atlantic Ave.

If Seattle is doing something similar (I'm not familiar with the specifics of the SR99 project) that should be a bet positive for traffic flow. If not, then, well, sucks to be in Seattle.

To my knowledge there is no plan to improve surface streets to accommodate this traffic.

[1]: http://cnu.civicactions.net/resources/publications/alaskan-w...

[2]: http://www.wsdot.wa.gov/Projects/Viaduct/Faqs

Downtown streets are traditionally built that way because they are two dimensional. This tunnel exists in the 3rd dimension.

If you live and/or work in the area -- and I have, although I don't currently -- this is not a good thing.

Only on HN would someone mod down the assertion, "The whole reason for building roads is to get people and goods where they need to go." Next up for refutation: color of sky, followed by the wet-dry nature of water.

So the decision was made to tear down the viaduct and replace it. Why not reinforce it or even rebuild it in place with modern construction standards? Because the viaduct has another drawback besides its seismic vulnerabilities: it's big and ugly. Its removal would enhance property values along the Seattle waterfront tremendously. Reportedly, the developers who own the affected property are major contributors to the Seattle politicians who have the authority to make the final decision, so fixing the current viaduct was ruled out from the start. It was only a question of which less-effective solution would be adopted.

With a rebuild off the table, the remaining options included surface-only streets, with fewer lanes and more traffic lights; a cut-and-cover tunnel, which would completely disrupt traffic in the area during construction; and the solution that was eventually chosen, a deep tunnel through unstable and poorly-characterized soils that would have to be bored underneath major downtown buildings and thoroughfares. The tunnel would have about half of the viaduct's lane capacity, no room for future expansion, and no downtown exits at all, but it wouldn't threaten the all-important view of Puget Sound, and parts of the old viaduct route could remain in use during construction.

In other words, it was one of those politically-expedient solutions where lots of other peoples' money would be spent in the process of making very few people happy. Schadenfreude was the best-case outcome, since complaining about traffic is as popular around here as football in Texas or religion in Oklahoma. But we're now looking at one of the worst cases: the engineering behind the tunnel (and/or the $90 million custom machine that drills it) is proving to be inadequate to the job, so essentially no progress toward replacing the viaduct is being made at all. Drivers are fuming, lawyers are salivating, mild-mannered newspaper columnists are discovering their inner muckrakers... and seismologists are frowning and muttering ominously.

Imagine how much transit $4 billion could buy.

Slightly more than 3.5 miles of light rail if Boston is any comparison.[0]

[0]https://en.wikipedia.org/wiki/Green_Line_Extension

It's already a big heavy mass of concrete and steel, and was reinforced after the last earthquake, it's hard to imagine reinforcing it more.

We could rebuild and reinforce it on Mars for what the SR99 tunnel debacle is eventually going to cost us, in both direct and long-term economic impact.

I'm only being slightly hyperbolic here. By way of example, the Big Dig cost about 40% more than NASA's annual budget... and as I pointed out earlier, the Big Dig was an improvement project. The SR99 tunnel is not.

https://en.wikipedia.org/wiki/Alaskan_Way_Viaduct_replacemen... "The project is estimated to cost US$4.25 billion, with $2.8 billion coming from the state and federal governments"

http://www.seattletimes.com/seattle-news/transportation/bert... "overall costs for repair, including excavation of the giant repair-access vault, are expected to exceed $143 million."

http://news.nationalgeographic.com/news/2014/04/140422-mars-... "The expert panel puts the total cost of a 20-year program culminating in a manned mission to Mars in the range of $80 to $100 billion."

Keep in mind that the Big Dig's original cost estimate was something like $3 billion. Turned out to be closer to $24 billion. We're not very good at these things, it seems.

I guess I'm new to the West coast and Seattle area. What is it about this project that has everybody just flipping out of their minds?

I live north of King County, so I don't have any personal insights beyond what I've already posted. My main concern is how much responsibility the state will have to bear for cost overruns. SR99 is technically a state-level project, even though it has little relevance to anyone outside Seattle. It's safe to say Seattle will try very hard to make the rest of us pay for their mistakes.

IIRC the people of Seattle and their government did not exactly push hard for the current plan? There was a referendum in which both the tunnel option and reinforcing the viaduct did not garner popular support, although reinforcement got more votes than a tunnel.

I think in this case "it's safe to say everyone is going to have to pay for everyone's mistake" is more fair. And certainly SR99 has impact outside Seattle, since Seattle is a huge part of the WA economy and basically anything that has impact in Seattle, has impact in WA.

Basically, it's because it's the second project in two decades where the will of Seattle voters has been totally ignored in favor of moneyed interests and the state government fucking with (and fucking over) Seattle infrastructure. The first project which ended up (finally) with a pretty sorry excuse for a light rail system between downtown Seattle and the airport, was constructed only after intense lobbying against which was, for a time, a much more popular (and extensive) monorail project. Several referendums were conducted over the course of about seven or eight years starting in the mid-nineties, and they went something like this:

1. Referendum for light rail - passes.

(much faffing about)

2. Referendum for monorail instead - passes.

(faffing about)

3. Another referendum for monorail - passes.

(faffing about)

4. Yet another fucking referendum for monorail - barely passes.

(faffing about)

5. One last referendum to actually go ahead and, you know, build the damn thing, amidst heavy lobbying against - fails.

And then Seattle gets a shitty light rail system that no one uses and hardly goes anywhere. Strangely, the moneyed interests that lobbied most against the monorail, become even more moneyed. And meanwhile, of course, other forms of public transportation i.e. buses have been allowed to rot.

And then right at the tail end of that mess came the earthquake, and the pressing need to overhaul/replace the AWV, and pretty much all the same political fuckery came out and made a total mess of that process in pretty much the same fashion as it had public transport.

I think, at the end of the day, there is a perception - and it is not totally incorrect - that there are a lot of registered voters in other parts of Washington State, particularly the eastern half of the state, who hate the Seattle metro area and the people who live there, and that this is reflected in the state government, and that when it comes time for infrastructure projects which will help to grow that part of the state which contributes most to Washington's economy, there is little political will in the state government to do the right thing. And so the success of Seattle is often in spite of the apathy, and occasionally even the active antipathy, of the rest of the state.

https://en.wikipedia.org/wiki/Cypress_Street_Viaduct