Ask Sound Transit to Study Sending Ballard and West Seattle Trains Through the Existing Tunnel

The deadline for comments on studies for the West Seattle and Ballard Link extensions is today. Please ask the board to study sending the trains into the existing tunnel, rather than building a new one.

Benefit to Riders

From a rider standpoint, reusing the existing tunnel would be fairly simple. All the trains would mix, just as East Link will mix with the main line. Transfers would be much better. Same-direction transfers would be trivial (e. g. Rainier Valley to the UW). Simply step off the train and wait for a different one (on the same platform). Even reverse direction transfers would be fairly easy (e. g. Seattle Center to the UW). Just go up and over, using the existing stairs, escalators and elevators.

In contrast, the proposed transfers vary from bad to terrible. Simply going the same direction could take anywhere from three to five minutes, maybe worse. For many this will mean a new, onerous transfer (e. g. Rainier Valley to the UW). For others, an unnecessary hindrance to the new addition. Someone going from downtown Bellevue to Denny might very well ignore the new tunnel and new line, given the poor transfer experience.

Travel to and from downtown would be worse for most riders as well. The stations in the new tunnel are not as good as the old ones. They are deeper, and there are fewer of them. The vast majority of riders, given the choice, would prefer using the stations inside the old tunnel.

Possible Issues

Sound Transit has expressed fear that the trains downtown would simply be overloaded. I seriously doubt it. As a city and a nation, we are rapidly becoming less peak-oriented. There is still a rush hour, but from a transit standpoint, a smaller percentage of trips occur during this time. With some work, it is quite possible the trains could run every 90 seconds, according to Sound Transit. Even running them every 2 minutes would provide the same potential throughput (30 trains an hour through downtown) as a second tunnel could provide. Running the trains more often would require elevating or burying the tracks in Rainier Valley - something Sound Transit has never even considered. But it is also quite possible that we never see 6 minute trains in Rainier Valley anyway, which means the downtown tunnel could handle the extra load with ease.

In the highly unlikely event that we do have capacity issues during rush-hour, there is a very simple, much less costly solution: run express buses. There are plenty of riders who would love to have their express buses back. You wouldn't need to bring all of them back, just the ones that have proven very popular. For both train and bus riders, reusing the existing tunnel is better.

Sound Transit has suggested that getting rid of the tunnel would be Not consistent with ST3 plan". If find this hard to fathom, given they are studying the elimination of stations like Avalon and Interbay (Dravus). Unlike those changes, this would actually be better for riders, not worse. To the extent that people even care about a new tunnel, I'm quite confident they prefer better transfers with better downtown stations.

There are other technical issues that may make it difficult to reuse the tunnel. That is why a study is needed. It is possible that mixing the tracks (otherwise known as interlining) is more disruptive and expensive than adding three new stations (and a tunnel). I doubt it, but stranger things have happened. That is why it makes sense to study the technical issues, to get an idea of the various trade-offs.

Deadlines for comments are today. Please let the board know you want them to study reusing the existing downtown tunnel for West Seattle to Ballard Link.