Yesterday afternoon, the Sound Transit Capital Committee met to hear a presentation (PDF) on the release of East Link’s Supplemental Draft Environment Impact Statement (SDEIS). Since the release of the original DEIS in December of 2008, a number of new alternatives and modifications have been proposed, including four new downtown alignments (C9A, C11A, C9T, C14E), a significantly modified B3 alignment, B2M, and a modified D2A. There aren’t very many surprises in the SDEIS, outside of what we’ve already discovered in Sound Transit’s concept design reports (here and here).
Of biggest interest, but not to any great surprise, is the update of the B and C segments, of which debates have yielded the most theatrical spectacles. The newish B3 “114th design option” is a more radical alternative to the original B3, which curved away from 112th Ave to avoid Surrey Downs. The new design takes the curve further east out toward 405, likely costing a good amount more than the original. What the justification is for the modification isn’t really clear. A few of the updates to the B7/BNSF alignment include the completion of the I-405 widening project and a new WSDOT sound wall between the freeway and 118th.
More below the jump.
A few things haven’t changed. B7 continues to score the worst on ridership, cost, businesses displacements, and has greater direct environmental impacts. Also of note is the consideration of the peat movement in the Mercer Slough, which would present a high construction risk in crossing the slough for the B7 route. While the SDEIS did not quantify the construction risks, the evaluation summary does state that the risks remain high, as even WSDOT has had trouble dealing with the existing I-90 bridges. This remains a huge “if” for B7.
There also aren’t many surprises from the downtown alternatives. The four new routes have already been covered pretty well in the concept design report and the numbers haven’t shifted too much. Both C11A and C9T continue to be the stars of the show in terms of coverage and ridership. Though slightly cheaper, Kevin Wallace’s C14E “Vision Line” still fares the worst in ridership– its system-wide numbers are only comparable because its speed poaches riders from Overlake and Redmond, making the line more of a bypass than anything.
Another modification of note is the D2A- NE 24th Design Option, which is actually the original D2 option that would have traveled at-grade through the Overlake area, stopping at the Overlake Village TC (currently Overlake P&R), and continuing along 520 to the Overlake TC. Since then, an alternative has come up for the route to stick to 520, with the Overlake Village Station right off the freeway– Redmond has offered to fund a walkway between the freeway station and the Overlake P&R (sound familiar?).
The new option is a bit of a double-edged sword. Its benefits include faster travel times by sticking to the freeway, cheaper costs with a shorter guideway, fewer business displacements by avoiding the neighborhood, and higher ridership– the caveat being that this is nothing more than Overlake’s own version of the Vision Line. Even with the long walkway aside, you’re still poaching riders from other stations further out, catering to commuters and not transit-dependent populations, and missing out on what could be a good walkshed in a neighborhood that has already seen partiality to TOD.
I think the real success of East Link comes down to how useful the system will be and for whom. If its a choice between a faster, less-accessible commuter-oriented line and a slower line with better coverage for all-day transit users, then I’ll pick the latter. Sticking too much to the freeway really starts muddling the gap with mere high-capacity express service, and that’s not something the voters had in mind with ST2.