Notes on the Alaskan Way Viaduct Replacement Project Final EIS
Ten years in the making, WSDOT released the Final Environmental Impact Statement for the Viaduct Replacement Project last week. It's a massive document: 286 pages and 23 appendices. The best one can do reading it is poke at it from a few different angles, do some treasure hunting and share notes. Here's what seemed of note to me.
Diving right in, I was immediately struck by how Surface/Transit was not evaluated as an alternative to the bored tunnel as it was in the draft and supplemental statements. The reason why:
The Surface Alternative was eliminated because traffic information presented in the 2004 Draft EIS demonstrated that it reduced roadway capacity, which didn’t meet the project's purpose as defined in the 2004 Draft EIS. The Surface Alternative proposed to replace the viaduct with a six-lane surface street on Alaskan Way. A six-lane surface street would reduce roadway capacity on SR 99 through downtown by 40 to 50 percent by 2030, leading to projections of increased travel times and congestion for drivers on SR 99 and other parallel roadways such as city streets and I-5. For some trips, travel times with the Surface Alternative would double, and traffic on Alaskan Way itself would have increased nearly sevenfold.
The bored tunnel, on the other hand, reduces SR-99 traffic to the point that for surrounding areas it's about the equivalent to having no viaduct at all, according to the Sightline Institute:
[C]ompared with an earthquake that closes the Viaduct, the state says that the tolled bored tunnel would modestly reduce traffic volumes in lower Queen Anne, on streets in the downtown core, and reduce them a bit more in Alaskan Way through Sodo. But the bored tunnel would make traffic a little worse in South Lake Union. And it’s basically the same as an earthquake for the waterfront, First Hill and Capitol Hill, and traffic crossing between Sodo and the ID/Pioneer Square
They're right. Looking at the traffic impacts with various alternatives (Chapter 5, page 118), the tolled tunnel doesn't make too much of a difference than just not having the viaduct. This is even moreso the case with Alaskan Way traffic overflow -- see fig. 5-19: figure 5-19 pg 122 (emphasis mine). With every segment north of King Street, traffic gets worse with tolled options, including the tunnel:
WSDOT Viaduct Replacement Project Final EIS, July 2011.
Sightline again:
[T]he state neglected to model a lower-cost “Streets, Transit, and I-5” alternative... I suspect that overall traffic performance [of Surface/Transit] falls somewhere as it did in previous modeling exercises: that is, with slightly better downtown traffic performance than the tolled tunnel, with much lower cost.
Of course, as they also point out, all tolled options perform similarly to the tolled tunnel -- mostly, what they say is at issue is "putting high tolls on a single link in a larger urban transportation network."
Have we mentioned that Surface/Transit is a lot cheaper?
Speaking of those traffic diversions, Chapter 5 examines permanent effects, mostly modeled on the year 2030 (see above).
The viaduct serves traffic headed into and out of downtown Seattle and traffic traveling through the downtown area. A large portion of travelers using the viaduct, 44 percent, are heading to or coming from Seattle's downtown central business district. Approximately 23 percent of travelers travel through downtown and are destined for nearby locations just north or south of downtown, such as south of downtown (SODO), Capitol Hill, Queen Anne, or South Lake Union. The remaining 33 percent of travelers are making longer-distance through trips, such as trips from Ballard to Burien. This means that the majority of trips, 56 percent, are through trips. The people and businesses in all these areas depend on SR 99 directly for their daily travel, or indirectly, as SR 99 takes trips that otherwise would crowd other regional roadways such as I-5.
The "large portion" of Viaduct travelers, 44 percent, will be dumped onto I-5 -- just not for through trips, which is... good? Personally, I don't know many people who are willing to take I-5 to downtown.
Page 130 shows tables of commute times. The bored tunnel has highest commute times, especially with tolls, with only a couple of exceptions. The difference is especially drastic for those commuting to or from West Seattle.
The Bored Tunnel Alternative with or without tolls does not replace the Elliott and Western ramps, which results in longer travel times for this alternative as compared to the Cut-and-Cover Tunnel and Elevated Structure Alternatives with or without tolls. With the Bored Tunnel, drivers could choose to get to northwest Seattle either by exiting SR 99 near the stadiums and continuing north on Alaskan Way, or they could choose to travel through the bored tunnel and exit SR 99 using ramps at Republican Street to connect with Mercer Street. For the tolled alternatives, southbound travel times during the morning commute are expected to be 18 to 20 minutes for the Tolled Bored Tunnel compared to 15 and 16 minutes for the Tolled Elevated Structure and Cut-and-Cover Tunnel, respectively. Northbound trips are expected to take 24 to 27 minutes with the Tolled Bored Tunnel, compared to 17 and 26 minutes for the Tolled Cut-and-Cover Tunnel and Elevated Structure, respectively.
From the Draft EIS for Surface/Transit, 2004:
WSDOT Surface/Transit Draft EIS, March 2004.
That 33-minute northbound trip is pretty scary, but not that much more scary than 27 minutes. Plus, we haven't seen what comes out of testing Surface/Transit with updated models, as with the alternatives discussed in the Final EIS.
The effects of tolling are overall pretty fascinating, and they're kind of like EIS easter eggs. Like this, from the 258-page Appendix H, which examines the social effects of tolling:
The evaluation of social effects of tolling considers those who would choose to
use the tolled facility and those who would choose to avoid using the tolled
facility. Alternate routes to and from social resources, social service providers,
and neighborhoods within the study area would enable travelers to avoid the
toll but still reach their destination. Reasonable access to social service
providers and neighborhoods would be maintained. However, under all three
of the build alternatives with tolling, travel times and congestion on local streets
would increase, especially during peak travel hours. Therefore, those who
choose to avoid the tolled facility could ultimately spend more time commuting
to social resources than they would under non-tolled conditions, in addition to
spending less time in other social activities. In some cases, people may choose
to patronize a social resource in a different location, if available, or avoid
visiting certain neighborhoods during certain times of the day or altogether.
Those who use the tolled facility would experience quicker travel times and less
congestion than they would experience on the non-tolled facility.
In a nutshell: People who can't afford pay tolls and need to get to social resources can ultimately just spend more time commuting, but still get there. Eventually.
Another feature often mentioned while discussing the bored tunnel is how it won't disrupt traffic during construction because the current viaduct may remain open. This is something I'm not too attached to, as it's terrifying enough without construction going on underneath it. And because, although SR-99 construction, whatever we do, will take several years, that's all the more reason to choose the right, sustainable long-term alternative the first time around.
From Chapter 7:
The project has a minor contribution to the adverse cumulative effects to
historic and archaeological resources that is mitigated through the Memorandum of Agreement with the State Historic Preservation Office. In addition, WSDOT notes that the City has a strong commitment to protecting its cultural heritage as do a number of groups in the region including Historic Seattle and Washington Trust for Historic Preservation, among others.
Earlier in the chapter, WSDOT mentions environmental effects of various alternatives -- for example, any tunnel option could divert groundwater flow, and could raise the water table. The tunnels would also not be put at risk by the anticipated 2-4 foot sea level rise over the next 50-100 years that would happen with or without the tunnels.
A little blip on the news radar last week came from some environmentalists coming out in favor of the tunnel, and WSDOT putting them forward at a press conference like liberal trophies. As Publicola pointed out, most environmental groups in the state that typically deal with transportation issues were not included.
The final chapter, before the appendices that are longer reads than the main body of the EIS, details how public input has been used in the process. It has, in the details of the project, including:
- Elimination of the Battery Street Flyover Detour, an idea from the 2004 EIS.
- Considering multiple construction plans instead of just one, which changed for the 2006 EIS.
- An addition of a tunnel lid near Pike Place for the cut-and-cover alternative.
- The inclusion of tolled versus non-tolled versions of all the alternatives in the Final EIS.
So, at the very least, WSDOT is listening-ish -- I guess we'll see if they're listening on the big-picture level of Referendum 1 is voted down.
The WSDOT Viaduct Replacement Project replaces our current SR-99 viaduct from around King Street to the Battery Street Tunnel. Demolition of the southern end is slated to begin later this year; removal of the Alaskan Way Viaduct is scheduled to be completed around 2016.
The full Final EIS for the Viaduct Replacement Project is available in PDF form, in its entirety, from WSDOT. Nerds: if you read it and find anything good, let us know on Twitter, Facebook or in the comments below.
