Build the Best Parts First

This Thursday the full Sound Transit Board is likely to permanently determine whether the agency's recent analysis of downtown tunnel alternatives warrants further consideration. It's no exaggeration to say the future of the Link light rail system is at stake. The latest estimates show the agency faces a $34.5 billion shortfall over the next 20 years. Once again, Sound Transit must choose what to do now, and what to defer to the future.

Many transit advocates are calling for Sound Transit to simply Build The Damn Trains, apparently expecting the agency to magically find a progressive pot of gold to fill the hole. Sound Transit will build what it can. What it should do is Build the Best Parts First.

Fiscal Limits are Real, Whether We Like It or Not

With most of the flagship ST3 projects in the environmental review and planning stages, the latest long-range financial update shows under the current plan, Sound Transit expenditures will begin outstripping revenues in 2033 and will continue to do so until the major capital projects are expected to be finished in 2042. There are no secret financial tricks the agency can pull to bridge the gap. It can either raise revenue or reduce costs; most likely, it needs to do both.

Unfortunately, the agency faces a federal administration unfriendly to mass transit and a state governor unfriendly to new taxes. Additional taxes at the city or county level might help, but implementation is likely to be years away. Realistically, if we want Sound Transit to move forward on building anything now, it can only start building what it knows it can afford. This isn't the first time: funding shortfalls forced truncation of the first Link project, delays and deferrals on multiple ST2 projects, and the 2021 Realignment of the agency's capital program.

This year, Sound Transit revealed new cost estimates for the Link extensions authorized under ST3. These increases, along with some decreases elsewhere in the program, total up to $20 billion in current-year dollars. When multiplied by expected inflation over coming decades, these cost increases become $30 billion of the $34.5 billion long-range shortfall.

The Ballard and West Seattle Link Extensions alone are responsible for $14.5 billion of the projected $20 billion in cost increases relative to the affordable plan. The remaining $5.5 billion is spread across the Everett, South Kirkland-Issaquah, and Tacoma Dome Link Extensions, and other projects.

Regional Savings with Regional Impact

Sound Transit's service area is divided into five subareas, and revenues are generally supposed to be spent in the subarea they came from. One of the great regional compromises of ST3 was the determination that every subarea would contribute to the cost to build the section of the Ballard Link Extension between Westlake and SODO, colloquially known as the 2nd Downtown Seattle Transit Tunnel (DSTT2).

However, despite being billed as a regional asset, the Preferred Alignment for DSTT2 would result in arduous transfers for most riders of the planned 3 Line connecting Ballard to Tacoma. Meanwhile, the original DSTT would continue to be saturated with riders from the future 1 Line (Everett to West Seattle) and 2 Line (Redmond to Mariner). Examples of future trips with arduous transfers include Rainier Valley to U-District, Eastside to airport, Lynnwood to airport, Des Moines to Capitol Hill, Federal Way to U-District, and Tacoma to Bellevue.

The main selling point of DSTT2 has become its ability to continue operating if there are issues with the original DSTT. However, that won't help 2/3 Line passengers: there are no crossover tracks between the tunnels, there wouldn't be room for all those trains in the other tunnel anyway, and passengers would be bottlenecked by transfers.

Today the savings from deferring DSTT2 is projected at nearly $8.4 billion. If these savings were divided equally among the subareas, it would practically cover the overages expected for the Everett and Tacoma Dome Link extensions. Do we really need DSTT2, or was it included under the assumption that regardless of the cost, it would be worthwhile? If we can't afford it, what would it look like instead?

The Ballard Stub

When the design of DSTT2 came to light and station locations became a political battle, advocates began to seriously question whether it was really suitable as permanent transportation infrastructure that we've got one shot at to build right. At Claudia Balducci's behest, Sound Transit finally studied the idea. Much like the agency's review of a potential shallow station under 4th Avenue, the popular armchair transit planner idea of connecting the Ballard Link Extension to the current downtown tunnel was determined to be incredibly risky and impractical. However, the agency's study of a stub-end line from Ballard to Westlake shows promise.

The clear drawback to a Ballard Stub is the lack of connection to a train maintenance base, but there's an extraordinarily convenient solution: the National Guard's Interbay Armory. The National Guard announced in 2019 that the armory was no longer meeting its needs and that it intended to move to a site in North Bend. As property of the state of Washington, the land could possibly be transferred to Sound Transit for free. Crucially, it has plenty of space and is flat enough for relatively easy conversion to a rail maintenance facility.

The downtown terminal of the Ballard Line would be an extension of the current Westlake Station, but the thousands to tens of thousands of daily riders would need a truly seamless transfer within Westlake Station. This is where some of the savings of not building DSTT2 could be readily reused.

A True Regional Upgrade

The original DSTT was built for buses at a time when Seattle and its suburbs had half the population they have today. Sure, it had some token rails, but those rails had to be torn out for Link and Sound Transit has had to contend with the tunnel's aging infrastructure as more and more regional riders are funneled through its passages. In its study of downtown tunnel alternatives, Sound Transit allocated an allowance" of $1-3 billion in potential fire safety, signals, basic throughout capacity improvements, and more. Upgrading the DSTT for very-high-capacity transit use was an original candidate project for ST3, but was abandoned in favor of the proposed DSTT2. This has turned out to be a poor choice.

Downtown transit riders are familiar with the current tunnel's limitations, and these limitations would not be improved with the construction of DSTT2. We should upgrade our existing infrastructure today instead of waiting until we might be able to afford a redundant tunnel tomorrow. That way, when the Ballard Stub opens, transferring riders will actually have seamless transfers.

Our Second Chance

DSTT2, as currently designed, is awful. It has to dive deep under SLU to avoid skyscraper foundations and will be even deeper under downtown due to our infamous topography. An unfortunate political process resulted in massively expensive and inefficiently-located stations. The new stations would do little to expand the walkshed of downtown transit. The proposed DSTT2 puts rider experience last and will fail as to serve as a regional asset. Conversely, the original DSTT is a true regional asset and if high-frequency trains operations might be unreliable with its current setup, then we should fix it, not leave it to crumble while we build a new redundant route.

Deferring DSTT2 gives us a chance to do something even more ambitious than ST3 imagined: take another shot at bringing high-capacity transit to a neighborhoods that need it. It's clear that a future ballot measure or another revenue source is needed to finish what ST3 started, just like how ST3 finished ST2 projects, and ST2 finished Sound Move. However, voters will also expect to get something new; not just something they were promised in 2016. The Seattle Transportation Plan identifies potential future light rail corridors. Among others, a future eastward extension from the Ballard Stub's Westlake terminus could be used to bring new connections to underserved neighborhoods instead of bringing redundant rail to a densely-served core.

Downstream Benefits

Ditching DSTT2 opens up several other opportunities, too. The West Seattle Link Extension is currently planned to serve as a stub line between West Seattle and an expanded SODO station for at least 5 years. If DSTT2 is deferred and the original tunnel upgraded in time, the West Seattle line could provide a one-seat ride to North Seattle or beyond on its opening day.

With a small maintenance facility (OMF) tied only to the Ballard Line, the Interbay OMF could serve as a testbed for automation. Sound Transit's Series 3 vehicles are expected to be twice as long as the current railcars and compatible with autonomous operations. Although driverless operations are far away for Link lines with at-grade sections, fully-grade-separated lines such as the Ballard and West Seattle lines could be upgraded to driverless operations sooner than the others, allowing for more operational flexibility and reduced operating costs.

The Delay Illusion

Ultimately, deferring the 2nd Downtown Tunnel should be a serious consideration for the Board. The main counterargument is the recognition that significant changes in alignment would require additional years of environmental review and engineering design. However, without reducing the scope of any projects, the Board will be forced to delay construction regardless. How long will Sound Transit have to wait to afford a $22 billion Ballard Link Extension? The 2021 Realignment already delayed the project 4 to 7 years to build a $12 billion line. How many more years would the agency need to wait to afford a $22 billion line? If couple years of delay results could save billions, that seems more than worthwhile - it seems like the most prudent choice the Board has.