I think there’s a killer argument here that’s hard to refute, and hasn’t come up yet, and in the interest of continuing this conversation, I’ll just post it!
Our viaduct options are basically a) build something else, and b) tear down the failing structure and leave it torn down. I don’t really consider the retrofit an option – WSDOT will probably shoot it down as unfeasible and unsafe.
So here’s the 2000 pound elephant in the room. For the first several years of implementation, both of these options look exactly the same. The old structure has to be torn down, and even in the best case rebuild scenario, you still have complete closure for years.
Immediately, every viaduct user finds a solution to their commute problem. They get on I-5, or they take a bus, or they plan ahead and change jobs or move before the mess starts – they’ll have plenty of lead time.
Two years later? They’re still doing it. I-5 can only carry so much traffic – it’ll worsen the most at first, but traffic will taper off after this time. Most people will have solved their problems, many more will be interested in transit and trying out the bus service we already have (and maybe ‘Rapid Ride’). I don’t know when this would be – maybe 2012, maybe 2014. Link Light Rail will be rocking our socks off. University Link will be mostly complete – everyone will be holding their breaths for subway stations. Maybe we’ll even have passed Sound Transit 2 by then, and Northgate and Bellevue will be groundbreaking soon.
Another year. Gas will be $8/gallon, or $10/gallon. Maybe speculative bidding on oil futures will have dropped off, and it’ll only be $6/gallon – this scenario doesn’t require $10 gas. A lot more of the urban condo projects will be done. Developers will be continuing to build in the core, and the renewed demand from people previously commuting across downtown Seattle will help bolster that. Again, all this is regardless of what we choose. Few commuters will just grin and bear it.
One more – say 2016. Four years of closure – the minimum on any of the WSDOT construction alternatives I’ve seen. This is where our choice matters. In scenario a), we have a new freeway. U Link opens. Some people return to their cars. The waterfront is dead – construction kills some of the businesses, and with the viaduct another 20 feet closer, it’s no longer pleasant. By this time, fewer are driving, and it looks like 5 won’t be as congested because so many people can’t afford to anymore. But we have a new freeway that we’ve already gotten used to not using.
In scenario b), the waterfront is still dead from construction, but now it has the chance to come back. Seattle has rebuilt the waterfront streetcar line, and four new mixed use buildings are on the way in the old shadow. The same pressures exist to build high capacity transit – the city is ripe for a new western corridor ballot measure. U Link opens, Bellevue is 50% complete, and Northgate is 70% complete. Sound Transit is ready to go to ballot with ST3, where North King money won’t quite cover Ballard-West Seattle, but will cover Ballard-Downtown, including a tunnel under 2nd Avenue. The city puts another measure on the ballot to build the other half. With new city residents clamoring for transit, Sounder ridership at 20,000 a day and climbing, and ST3 Link expansion promising Tacoma, Redmond, and most of the way to Everett, both pass.