DR: Describe what the surface option would look like.

CM: The first thing is a regular four-lane street on the waterfront, which is what all the tunnel proponents say they’re really after.

Waterfront street, artist's renderingA cross-section of what a waterfront surface street could look like. Exact design details are being worked out by James Corner Field Operations.People’s Waterfront Coalition

Heavy transit investment in three main corridors: West Seattle to downtown, Ballard to downtown, and Aurora North to downtown. Probably bus rapid transit to start. We still need to figure out the exact details. McGinn is interested in light rail, but a lot of people think that takes too long and we need something fast and now. I would push for bus rapid transit now. As we create demand for transit, put in light rail on the routes that need it.

A vision for Seattle's waterfrontA (somewhat vague) rendering of the view of Seattle’s waterfront from Victor Steinbrueck park.People’s Waterfront Coalition

Improvements to I-5. Without increasing the footprint, you can rearrange the way the on- and off-ramps work and get a third northbound lane through downtown — just using the pavement we have more efficiently. All the through-trips trying to bypass the city can fit there. Similar tweaks to southbound can get 20 percent more throughput, which is plenty for the bypass trips.

Then a lot of small improvements throughout the street grid, to give transit better priority, to increase connectivity in neighborhoods, so that some of the streets that are parallel to the viaduct but aren’t very well-used could be better-used. In the South Lake Union neighborhood, for instance, all these wide streets are at about half capacity or less. If we could fix the intersections across Denny and Mercer, all those streets could be more useful.

Then, aggressive demand management, commute-trip reduction, carpooling. All those things are really cheap, and they add up. You can encourage about 25 percent of the trips not to happen through use of those programs.

DR: How much would the surface street option cost?

CM: It’s about a billion dollars less than the tunnel. That’s recently been affirmed by the director of SDOT. They’re all small projects.

DR: It also seems more resilient. If you have cost overruns, there are incremental ways of dialing back. There are no increments in a tunnel.

CM: Well said. Apples to apples, if you add up the city’s and state’s projects for the tunnel, it’s $4.2 billion. The surface/transit/I-5 solution would be $3.3 billion.

DR: Describe for us what the tunnel would look like, where it would be, and who would go through it.

The proposed Seattle deep-bore tunnelThe proposed tunnel.WSDOTCM: There would be two lanes each way {this info is in the next para}. The south portal, where it goes underground, is at Alaskan Way and King Street, right next to the Pioneer Square Historic District. Then it would stay along the waterfront
for a bit, go under downtown diagonally, and come out at 6th Avenue and Roy, right by the Gates Foundation, and hook up with SR-99.

There would be no exits. No transit, because there aren’t any transit routes that bypass downtown. No bikes, obviously. The emergency egress is also quite interesting: If there is accident or fire and you need to get out, you have to walk to either end. There are no elevators or stairs. What if you’re on crutches, or in a wheelchair, or sick? You just have to wait until someone comes to rescue you. And the shoulders are tiny, just two feet and six feet, so it’s not like there is a lot of room for emergency vehicles if there’s congestion.

A gigantic tunnel boring machine.The tunnel boring machine used to dig Madrid’s M-30 tunnel.UrbanScraperDR: Are we talking about a single, gigantic drill that’s going to start drilling under Seattle?

CM: Yes. It’s 55 or 56 feet across and something like 400 feet long. If it gets stuck, like if it bumps into a boulder, how would you ever get it out, repair it, or replace it? One of the tunnel experts hired by the city quoted a study that said one out of three boring machines like this gets stuck and has to be repaired, replaced, or removed. How would you do that under downtown Seattle?

DR: You’re tunneling under some pretty old and historic parts of Seattle, too, especially by Pioneer Square, right?

The proposed route for Seattle's deep-bore tunnel.The propsed route for the tunnel.WSDOTCM: Yeah. They moved the alignment. They were going to do it right under 1st Avenue through Pioneer Square. They realized they couldn’t do that; there is just too much fragile stuff down there. So they moved it over to the waterfront, but it is still next to the Historic District, and then when it cuts diagonal, it goes underneath 14 historic buildings. Two of them are going to have to be removed, probably, because they can’t really repair them or protect them. Twelve are in harm’s way, but they feel like with jet grouting and monitoring and some money for repairs, they’ll be okay.

I haven’t told this to anybody in the media yet, because they don’t have it in writing, but I’ll just tell you: it goes under the historic Federal Building, and the federal government has never given rights to use land underneath their buildings. They just don’t do that. They’ve made that clear to WSDOT, but WSDOT is proceeding anyway. They’re moving forward as if that problem’s just going to go away.

DR: What’s going to happen now? If McGinn says Seattle isn’t going to sign onto an agreement until someone has committed to the cost overruns, what happens then?

CM: It’s not clear. Gregoire probably has enough authority to do this project without any cooperation from the city of Seattle.

DR: What? Seriously?

CM: If they decide that it is in the public good and local jurisdictions are not being helpful, they can take what they need and make it happen.

DR: Have they threatened to do that?

CM: I don’t know if they’ve said it in those words, but I think the city council recognizes that Seattle doesn’t have that much authority. That’s why they’re doing this play-nice, get-along routine rather than standing up for Seattle’s interests.