Ben Schiendelman, in a post at Seattle Transit Blog, has argued that the proposed deep-bore tunnel under Seattle could not be converted to transit use. He tells us that any transit line through Seattle must include 5-6 stops downtown, that the tunnel, at depths of 60 to 200 feet will make the cost of building those stations as much as a billion dollars per station, and therefore, it would be simpler to build a new subway than to convert the tunnel. The only remaining question is whether any of what he says is true.
Are there any deep-tunnel type subway systems? The Wikipedia entry for the London Underground describes 7 of London’s 11 lines as “deep level”, with the Bakerloo line reaching depths of 200 feet. A deep-tunnel subway would not be without precedent.
How many stations would you need downtown? Certainly not “five or six”- LINK itself only has four. I would go further and argue that NO stations are needed for the deep tunnel.
Seattle’s downtown, as large as it may appear to Seattle residents, is not actually that large. The distance between James and Pine is no more than 3-4 stops for a Manhattan local subway or 2 stops for an express. The area around each proposed tunnel mouth is developing rapidly, with some of the largest investors making it plain they consider these areas better investments than the exact center of the city.
When we couple these developments with surface transit and the small size of downtown, it seems very possible that it would be of value to have a transit line that did not become a local for twenty minutes traversing the city core. The tunnel, after all, is being built for people who do not want to go downtown, and presumably these people will still exist when the price of gas has driven them to transit.
Ben is adamant that people will not use transit that doesn’t deliver them to their door. Fortunately, we can again touch base with reality by watching the passengers commuting by ferry. Most of these passengers used a Kitsap Transit bus to reach the ferry dock, where they transferred to the ferry. Upon reaching Seattle, where no particular transit is offered at the ferry depot, almost all of them simply walk uphill to their destination or another transfer to a bus, or possibly two, taking them to their final destinations.
By an accident of geography, any traveler from south of Seattle to north of Seattle must pass through the ‘narrow waist’ of the city, or travel east of Lake Washington. If density were to increase on existing transportation corridors, it seems entirely probable to me that some transit users of the future would prefer to use a line that hardly stopped downtown at all. Unlike Ben, I consider it very likely that at some time in the future the proposed tunnel will be converted, at least in part, to transit use.
I could see a single stop working well here. Have it connect to the 3rd Ave tunnel via a pedestrian tunnel in one direction and out to the ferries in the other.
Of course, this car tunnel will be large enough for two lines, not just one. I’m picturing mass transit on the top level and freight on the lower level.
My active imagination sees just the stations at the tunnel entrances and a streetcar line stretching between them on the surface, with “a car in sight at all times”. By tapping ridership on a line through the tunnel, you could justify really superior service with streetcars that would really enhance the downtown core.
Thinking about freight is a reminder that Sounder may not always be as welcome on BNSF rails as it is today. The Salmon Bay liftbridge is not the only choking point on that system.
I don’t know if the snarkiness was really necessary. Your post and Ben’s don’t have to cancel each other out. I generally agree with Ben’s take of the situation and am of the opinion that the tunnel is a horrible idea. However, it is perfectly possible to have that opinion AND appreciate you pointing out that if we do actually get the tunnel, all hope for transit is not lost.
Ah, if only Ben agreed with you! Unfortunately, in replying to my comments at STB he used language that might justly be termed ‘snark-bait’. As though I weren’t naturally snarky and hard to get along with.
Ben has an unfortunate, obsessive need to be right, even about biased, unfounded personal predictions.
I suppose anything is possible (converting the deep bore), just like converting I-5 to dedicated ultra high speed rail lines someday, but the deep bore is really not a good place to have LRT. I’ll explain very breifly.
The best place to get off one train, and on the next going somewhere else is at the platform your on – not one several blocks walk away.
The current DSTT has the capacity to run trains every 2 minutes with proper signalling and control. In 2030, N. Link, will only run trains every 5 minutes each direction in the peak, accomodating 103,000 boardings in that segment.
A new LRT GREEN LINE could run from Ballard to W. Seattle, merging with the DSTT at CPS until SODO, running at 10 minute headways. This capacity more than handles the ridership projected by ETC. It is about the same as E. LInk (45,000 daily boardings)
The GREEN LINE transfer to both Airport and East Link trains would be at any of the downtown stations.
The capacity is there, and should be fully utilized as the best place to transfer and integrate all three lines.
Nothing improves reliability like a second chance- AKA, redundancy.
Oh, sure, I agree with you- if everything else went as currently planned, there would be no point to this discussion. If everything worked perfectly, there would be no point to having this discussion.
I just see a lot of variables that might, in the end, make it a good idea to convert the proposed tunnel.