Sound Transit Should Expedite Second Tunnel

The May 28^th Seattle Times, Traffic Lab article concerning the impact of Sound Transit’s second tunnel light rail station on Chinatown neighborhood again ignores the most important tunnel issue, it won’t be completed until 2035.  The 2016 Sound Transit 3 Map details the 1.7 mile tunnel will cost $1,638--$1,752 (2014 $M), include 4 stations, and add 110,000–136,000 daily riders. 

When completed in 2035 the ST3 Map indicates the new tunnel will connect the Ballard link with East Link.  The 5.4-mile Ballard Link will add 5 stations, cost $2,383--$2,550 (2014$M) and add 47,000 –57,000 daily riders (per ST3 Map).  It's not clear why Sound Transit chose to use the new tunnel to connect East Link with Ballard Link since most east side commuters would prefer connections to UW. 

The West Seattle Link, scheduled for completion in 2030, will connect with Central Link routed through existing Downtown Seattle Transit Tunnel (DSTT).  It will also add 5 stations, cost $1,431--$1.531 (2014$M) and add 32,000–37,000 daily riders (per ST3 Map)

Apparently, until the new tunnel is completed in 2035, both West Seattle Link and East Link will share Central Link’s DSTT tunnel capacity.  Sound Transit has claimed 42,000—52,000 daily by 2026 for East Link so the two extensions will add up to 89,000 daily riders to those riding Central Link. Apparently Sound Transit has its own way of estimating DSTT capacity since a 2004 PSRC study they funded limited tunnel capacity to 8880 riders per hour in each direction.

Clearly the Traffic Lab needs to demonstrate more concern about the need to expedite the second tunnel rather than the impact of a second light rail station on Chinatown.  The second tunnel and the Ballard and West Seattle light rail extensions will increase transit capacity into downtown Seattle.  The billions spent extending Central Link beyond University and SeaTac will do nothing to increase DSTT transit capacity into Seattle.

The second tunnel adds up to 136,000 daily transit riders, with 57,000 from Ballard. When finished it will avoid the need for East Link to share DSTT capacity with Central Link.  Ballard and West Seattle Link ridership benefit because 70 to 80% of riders are anticipated to live within walking distance of a light rail station, avoiding the need to spend $70,000-$100,000 for parking to provide access for a rider.  

(By comparison only 20-30% of potential riders for the Central Link extensions will live within walking distance of light rail stations.  Sound Transit refuses to provide access with added parking or local bus routes, choosing instead to force current bus riders to transfer to light rail; adding nothing to public transit ridership.)

Sound Transit budgets 4-car, light-rail-train operating costs at ~$100.00 per mile.  Thus each mile of light rail extension adds $200.00 to round trip costs.  The round trip costs for the 4.7 and 5.4 mile West Seattle and Ballard links are a fraction of costs for extensions to Everett and Tacoma.  Even worse, the former adds transit riders into Seattle, the Central Link extensions doesn't, requiring either a huge increase in fares for those riding, or subsidies to cover the increased operating cost.

The bottom line is the Seattle Times has conceded ST3 extensions won't reduce congestion.  It's too late to do anything about the billions and years Sound Transit wasted on an East Link that will increase not decrease I-90 corridor congestion.  Additional billions and years have already been spent on extensions beyond UW and SeaTac that do nothing to increase capacity into Seattle.

However, billions and years remain to be spent on Central Link extensions to Lynnwood and beyond, and to Federal Way and beyond.  The Seattle Times needs to recognize those funds should be diverted to allow expediting the second tunnel and the Ballard and West Seattle Links.  Something that will increase transit capacity into Seattle, reduce congestion, and far more important than the impact of a light rail station on Chinatown.