Sound Transit Presents ST3 Options

Sounder Bruce (Flickr)

Sound Transit 3 (ST3) kicked off in earnest today with a Sound Transit Board Workshop . The bulk of the information involved more detailed corridor studies to further assess various alternatives against the criteria the board set out. However, there was also an interesting look at the benefits of expanding the package from 15 to 20 or even 25 years, as well as absolutely fascinating operational concepts for the final system. We'll have a much more detailed look at financial models and operational concepts in the coming days, but here are some project highlights.

In the charts below, the five metrics we've shown are Spine (Yes/No), daily ridership, capital cost, annual operations and maintenance cost, and travel time for that segment. Click on each image for full details.

Snohomish County

Three main options were presented for getting to Everett, via Paine Field (N2A), SR 99 (N2B), and I-5 (N2C). There were few surprises for observers of last year's corridor study.

• Cost: Options range from a minimum of $2.9B for a a low cost I-5 alignment to nearly $5B to serve Paine Field. Depending on the options chosen, annualized cost per rider (over 30 years) would be $4-$7 for an I-5 alignment, and $7-$10 for Paine Field.
• Ridership: Relative to I-5, Paine Field increases cost by 50-70% while only generating 2,000 more riders. Projected ridership is 42,000-58,000 for all options on the table, numbers that are likely to be highly competitive for federal funds.
• Travel Time: Paine Field also costs riders 10-13 minutes of additional travel time. Travel time from Lynnwood-Everett ranges from 25 minutes for I-5, 31-34 minutes for ST 99, and 35-38 for Paine Field.

Downtown to Ballard

Four options were presented for Downtown to Ballard. Option C1A is a fully at-grade line that would reach Downtown via Interbay, Belltown, and then be interlined with the Center City Connector (CCC) on 1st Avenue. Option C1B is fully grade separated, elevated from Ballard to Lower Queen Anne and tunneled through South Lake Union and Downtown. Option C1C is identical to C1B except for running through the west side of Interbay rather than along 15th Avenue West. Finally, Option C1D is the "Westlake Rapid Streetcar" option, which like C1A would also interline with the Center City Connector on 1st Avenue.

The grade separated options accept SDOT's suggestion for a South Lake Union at Westlake/Denny, although they treat SDOT's other station requests (SR 99/Harrison and W Newton Street) as separate projects.

In a departure from ST's Conceptual Studies from last April, there is no longer an at-grade option for Ballard that includes a new Downtown tunnel, as ST has determined that due to the elevation of any Lower Queen Anne tunnel portal, descending to at-grade only to elevate again over the Ship Canal is actually more operationally complex than a pure elevated line.

• Cost: There is a huge range of estimated costs, from as little as $1.7B for the Westlake Avenue option to as much as $5B for the fully grade separated options, or nearly $700m per mile (15% more per mile than ULink!).
• Ridership: By grouping a new Downtown tunnel into the Ballard project, instead of West Seattle as in previous studies, the ridership results are truly astounding for the grade separated options, 102,000-133,000 per day*. At grade options produce less than half that, 39,000-48,000 for Westlake and 44,000-54,000 for the Belltown option.
• Travel Time: Travel times from Ballard to Sodo range from 18-19 minutes for grade separated options, and 23-25 minutes for at-grade options.

Downtown to West Seattle

Three options were presented for Downtown to West Seattle. Option C3A would emerge from a new Downtown tunnel and run elevated to Alaska Junction, with a new fixed structure over the Duwamish River and new stations in Sodo and Delridge. Option C3B would run at-grade along 1st Avenue before elevating to reach Alaska Junction. Option C3C would emerge from a new Downtown tunnel and run elevated to Delridge, where it would turn south and run at-grade to White Center.

• Cost: There is little variation in project costs for West Seattle, with a range from $1.7B for a purely elevated line to Alaska Junction up to $2.0B to serve the additional 3.5 miles to White Center. Amazingly, the at-grade option to West Seattle is more expensive than the elevated option, due to freight conflicts, increased property takings, and the likely need to widen 1st Avenue South. The highest possible ridership Ballard to West Seattle line would cost no more than $7.1 billion.
• Ridership: Ridership varies wildly depending on the option chosen, from as few as 20,000 for the at-grade option to as many as 50,000 for an elevated line to the Junction.
• Travel Time: Travel time is 11 minutes from Sodo to the Junction, or 18 minutes from Sodo to White Center. nearly 3x faster than today's Route 120.

Overlake-Redmond

Perhaps the most sure thing in all of ST3, the Overlake-Redmond segment of East Link is included as Project E1, but with a new station shown near Marymoor Park. Ridership is 8,000-10,000 and comes in at $1B with a travel time of 8 minutes.

Totem Lake-Issaquah

Frustratingly, there's no direct comparison between BRT on the Cross Kirkland Corridor (E6) and Light Rail (E3) on the same span. Both connect to East Link at Wilburton, and Link continues on to Issaquah. Alignment details aren't cast in stone yet, but failing to directly serve Downtown Bellevue in the Link alternative seems like an early unforced error that can and should be fixed.

• Cost: Link from Totem Lake-Issaquah would cost roughly $3B, while BRT from Totem Lake to Bellevue via Downtown Kirkland would cost roughly $700m.
• Ridership: Ridership is lackluster for both Link and BRT, partly because they miss the heart of key demand generators. The BRT project is estimated at only 2,500-3,500 per day, while Link is estimated at 12,000-15,000. In either case, costs per rider for these projects are by far the highest of any major ST3 project under consideration, at $18-$27 per rider over 30 years.
• Travel Time: Link is estimated at 31 minutes from Totem Lake-Issaquah, and BRT is estimated at 35 minutes from Totem Lake-Bellevue.

I-405 BRT

All four I-405 BRT alternatives perform better than the Cross Kirkland Corridor projects. Yet interestingly, the study found no ridership difference between the high-investment and low-investment scenarios, apparently discounting the possibility that reliability would impact ridership. Ridership is 13,000-18,000 no matter whether ST spends $300m (Option E2A+E4) or $2.1 B (Options E2B+E4).

South King/Pierce

Including the unfunded segments from ST2, the study looked at I-5 and SR 99 alignments from Federal Way to Tacoma. Using SR99 adds nothing but cost because the two roads are so close together.

It's barely a "study," because all the numbers depend on BNSF negotations, but ST Executive Ric Ilgenfritz told us that expanded South Sounder would have the intent to move towards hourly all-day and evening service. The project would probably involve a third track to avoid freight conflicts. "We have enough train sets to do hourly, and once the track's there it's not that expensive to use the trains as much as you can." Along with more Sounder runs, bigger platforms, Tacoma Link to TCC, bus reliability projects deep into South Pierce County, station access improvements are all under consideration.

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Over the next week or so, we'll describe interesting operations and transfer concepts in store for Link, Tomorrow, we'll discuss the finance options, and we'll dive into some interesting study results in more detail.

*A major caveat here is that the Ballard ridership numbers include significant network effects and different operational scenarios for a 2nd Downtown tunnel, something we'll be writing about in the coming days.