above: a representation of why I-90 is a better choiceI'd imagine a fair portion of the people who read this blog already know some or all of these reasons that Link is going over I-90 before it goes over SR-520, but I thought I'd enumerate them for easy linking and just to fill in any holes.
I-90 offers a direct connection to the downtown Seattle transit tunnel. If you looked at my earlier tour of Central Link construction, I had a google maps link to the south transit tunnel entrance - you can see there the two tracks we've built, plus the space to either side where feeder tracks join with the I-90 center roadway. This kind of a connection offers us the opportunity to interline service - both trains going to the airport (or farther) and trains going to the eastside will come into downtown from the south and run on the same tracks in the tunnel.
It so happens that demand for the northern line (Northgate) is very close to the combined demand for an eastside line and a south line, so having East Link enter the tunnel from the south means that our commute patterns will much more efficiently use our infrastructure. This is also the big reason we didn't pick buses for building from Seattle to Bellevue - they couldn't efficiently interline with North Link to increase capacity there. With rail, people can get on a train in Redmond and go all the way to Northgate, without transferring.
If we were to cross 520, we'd have two choices, both of them bad: One, we could build a surface level station to transfer at Husky Stadium, and force a transfer for commuters to already full trains coming in from Northgate - we'd create crush loaded trains. The other option would be to build a direct connection into the tunnel toward downtown - which would cost hundreds of millions on its own, potentially have large construction impacts on a residential area, and could be risky due to the depth. Such work would probably also delay University Link.
Even ignoring the capacity and technical issues in Seattle, the eastside would have a problem of its own. 520 is significantly north of downtown Bellevue, so trains would have to turn south first to serve the Bellevue downtown core, then north again to get to Redmond. When using I-90, we don't have to go out of our way to serve south Bellevue, and the time between downtowns is lower.
Issaquah poses another problem with a 520 crossing.. We're already planning to build to Redmond, but if we chose 520, later construction to Issaquah (part of the Sound Transit long range plan) would really necessitate an I-90 crossing anyway. With an initial I-90 crossing, it's much simpler to continue east in or near the interstate right of way.
A 520 crossing would also impose any delays attached to construction of the new SR-520 bridge on Sound Transit's schedule. The risk added by working with WSDOT on the project would likely also make Sound Transit less competitive for Federal Transit Administration grants.
All this, and I-90's center roadway was built with conversion to high capacity transit in mind. I think it's always been the clear choice, but hopefully this convinces more people who were worried about the decision!
30 comments:
Seattle Post-Intelligencer just wrote an article that addressed some of the common concerns about cross I-90. Apparently, trains will have slow down when getting on the bridge and when leaving the bridge, but that doesn't sound like a huge deal.
I sure hope they listen to this.
Can't be that bad: compare the time you'll save even with slowing down slightly on the bridge with traveling north to UW, getting out of a train, climbing a few stairs, getting on a train again, and so on.
At first I was skeptical that I-90 light rail would work, as I have personally experienced the "hardship" of ST route 545. But, I gotta say, thanks to Ben, I now realize it's probably better to put light rail on I-90 first than 520. Heck, maybe it might save me some time in the future instead of taking the 545!
Can someone tell me with regard to East Link, will there be a transfer to the central link trains? Or will the East Lake converge directly with north-south bound trains? I am just having some difficulty wrapping my brain around how exactly the east link will connect to the central link system.
anonymous:
You won't have to transfer at all! :)
"Interlining" (that word I use) means that, in this case, your east link trains will come into Seattle and then just keep going on Central Link tracks northbound. Their first stop on Central Link tracks will be International District station, and they'll just keep going north from there.
The other direction, we'll probably have two colors of train or something - red line to the airport, blue line to Bellevue/Overlake. You'll see both red and blue trains at Northgate, and they'll split south of ID station.
Yeah, ballardcommuter, the slowdown won't be a big deal at all.
And the thing about the 545 - the 520 replacement project will speed that trip up an awful lot. I've been paying attention - I take it every day!
Here's the official SoundTransit document about this:
http://www.soundtransit.org/Documents/pdf/projects/eastlink/LoadBalance.pdf
Thanks for laying this out. I've heard or figured out some of these points, but not all of them, and certainly not all in one place. I-90 is clearly the better option.
I am curious how eventual expansion of the system will work. For example, if there's an extension to Issaquah, will that be a spur requiring a transfer in South Bellevue, or will it interline somehow with your "blue" line? What about extensions along the 405 corridor in both directions? I know that any Ballard/West Seattle extensions will require another tunnel.
I assume the Issaquah extension would just overlap the Bel-Red line on the I-90 crossing increasing the headways between S.Bellevue and Seattle. The beginnings of a network would appear if these interlinings are merely different lines crossing paths on their way to different destinations:
Everett/Redmond
Everett/Seatac/Tacoma
Issaquah/Seatac
Something like that.
if you are referring to the two empty lanes on either side of the tracks ... those are the road ways for the busses ...
you will have
UW - Airport
UW - East Side (wherever it goes)
East Side - Airport
it makes the junction more complicated since trains will need to go 3 different directions ... but it is simple engineering stuff.
eric ... the URL for the document about the loads on the I90 bridge is here:
http://www.soundtransit.org/Documents/pdf/projects/eastlink/I-90_load_test.pdf
Gordon, those two roadways to either side would be converted to rail. Currently, the buses drive directly on the rails you see in the map I linked to.
There will not be a wye that I'm aware of - no direct connection from the eastside to the airport until we build more of the long range plan. There's very little demand for Bellevue-Airport to justify running trains in that route.
Hey cas!
If you haven't, check out the old long range plan:
http://www.soundtransit.org/x2397.xml
(Also, I know they don't show West Seattle, which is part of why I think a city/ST partnership would happen there.)
Issaquah would interline with Bellevue on the bridge, adding service for Mercer Island and Rainier/I-90, and then turn northbound to go through downtown and serve Capitol Hill, UW, etc.
The 405 corridor will probably get its own service eventually. My hope would be building, in pieces, a giant loop line from Burien, West Seattle, 2nd Avenue, Ballard (or Fremont), up to Lynnwood, and then back down through Bothell, Kirkland, Bellevue, Renton, Tukwila back to Burien. Hit both downtowns.
Ben ... I'd say that would be bad planning ... a three-way junction shouldn't be that cost prohibitive ... and would be a boon in the long run. it is much more difficult to add a third connection AFTER the fact than at the same time.
anyway ... do east siders not fly? or are they too good for Light Rail?
;-)
G
Gordon, I think the importance of a one-seat ride may be overstated when a transfer means going to the opposite platform of a light rail station. Certainly if the mode and location of the transfer are the same it removes quite a bit of headache. It's not like a bus system, where everything is unintuitive and where there dozens stops on the average route.
Ben S, would the addition of an Issaquah route effectively double the smallest possible headway for Overlake because of bus tunnel issues?
Gordon, the issue is cost-benefit.
First, there's a capital cost problem. We already have ramps going directly into the tunnel in the direction we want them. For the opposite direction, we'd have to build new ramps entirely, in an area with a lot of other elevated infrastructure.
The real issue, though, is operating trains that go from bellevue to the airport. Very few people want to do that - we're talking about an order of magnitude fewer trips here. We'd have to tie up trains and service hours for a service that would get very little ridership, and drag down the overall efficiency of the system. The issue of transferring by crossing a platform is a pain, but it's a very small pain compared to the pain we would feel when we tried to pass another ballot measure with the opposition talking about empty trains and bad ridership statistics.
rizzuhjj, the headways I read about in the long range plan (2005) are 2.4 minutes for the tunnel (ID to Everett), 5 minutes for Tacoma, 7.5 minutes for Redmond, and 15 minutes for Issaquah. That's twice our current Issaquah service (from Sound Transit).
If we went down to 2 minutes in the tunnel, we could do 5 minute service to Tacoma, 5 minute service to Bellevue/Redmond, and 10 minute service to Issaquah. I don't know if that's feasible, but it would be adequate service.
I find it humorous that "capital costs" are a problem for rail on 520. My goodness, this is the most expensive light rail project (in terms of dollars per mile) in the USA. You'd think they would have quit before starting if they were concerned about cost. Priority in design: 1) Engineering marvels, 2) costs, and 3) ridership. Who would plan a rail line underneath the UW campus without a station at the Hub? Who would decide not to put in a station at First Hill?
Yes, I understand there was opposition to these proposals, but would you please stop pretending that Sound Transit's decision-making process is perfect and its engineering genius flawless?
Ben,
If the light rail plan requires every line to go through downtown, doesn't that in the end reduce the ability to provide more service on the ends? (Metro buses provide much more than 15-minute headways during the peak) I believe BART has this problem. Wouldn't it make sense for Issaquah to enjoy a line that goes to Bellevue, since they are on the Eastside and likely many people live in Issaquah to be close to major employment centers in Bellevue, not Seattle. So how is Link to downtown going to help them unless there is an additional line to Bellevue that effectively splits the headway in Issaquah and thereby provide more service (7.5 minutes in the peak) from Issaquah to Eastgate?
They might as well stick to the bus if they want to go to Bellevue, since using Link would mean transferring in Mercer Island then getting to the other side of the platform to reach an outbound train to Bellevue.
The Link plan, as seemingly "regional" as it is, tries to force everyone to downtown Seattle. You build these beautiful rail lines that are constrained to mediocre headways on the tails because of a singular bottleneck- the hourglass we call Seattle. Under the ST plan, only several miles of the system would enjoy 2-minute headways. And the designed-in constraints would ever constrain it to such. Why are we trying to remake the problems of geography in our transit service?
what is the projected travel time from Redmond to Seattle Westlake? Given the expected short headways, I don't see nearly as much problem with a two-seat ride. I get most of your points though
curmudgeon, we didn't build First Hill because it had projected ridership of 5,000 a day and would have cost us $1.1 billion - $350 million for the station, and $750 million because we would have raised our risk so much that we'd have lost the FTA grant.
The newest project in the US is always the most expensive, when you don't adjust for inflation. According to the FTA, University Link (the most expensive per mile) is the most cost effective per rider the US has seen in 25 years.
The UW told Sound Transit they wouldn't allow stations on campus. That's their prerogative.
Take your anti-Sound Transit rant elsewhere.
multimodal man, I'm sorry you have a problem with the region's layout, but Seattle's an order of magnitude larger job center than Bellevue, and that's going to continue to be the case. Bellevue largely developed as a node because congestion across the bridges created a high marginal cost for the last mile of a previously cheaper commute, as well as because of the limitations of the 1989 CAP initiative. With the removal of CAP and now East Link, a lot of that bottleneck will be gone. Seattle has the ports and the financial center (and that's not likely to change), so it's likely that Bellevue's growth will taper off.
If you look at commute patterns today, more people go from Issaquah to Seattle downtown than go from Issaquah to Bellevue downtown. Note that I specify downtown - that's where the light rail line will go, so that's all that really matters to the comparison.
In the future, as well, we'll see a 405 line (as you can see if you go to the Sound Transit long range plan). That'll mean one transfer (and rail to rail transfers aren't really an issue like bus to bus transfers are - I'm going to write about that at some point here. It's likely that a 405 line and an Issaquah line will happen in a similar timeframe.
multimodal man - one more thing. There's nothing keeping us from running trains Issaquah-Bellevue-Redmond if it looks like there's demand when we're building that line. So don't worry about it too much, you're talking about ST3 or ST4.
anonymous, which Redmond? From Overlake to Westlake would likely be 35 minutes, and from Redmond to Westlake would be 40. The two seat ride isn't as much of a problem as the crush load issue - but it's still silly to solve the much harder problem of connecting 520 when we have I-90 ready made.
What we don't want to do, in general, is replace current one-seat ride bus service (like the 550) with two seat rail rides. That doesn't end up giving us much benefit - regardless of whether a two seat ride is "that bad", it does significantly impact ridership.
As an Eastsider who goes downtown AND to the airport, the I-90 routing offers me nothing.
Of all the trial balloons being floated for the next ST referendum, none of them offer me anything.
Why would I vote for it again?
The I90 routing is essentially being built for carless Microsofties who live in North Seattle. It's useless for most Eastsiders.
brad, if you live on the eastside and go downtown and to the airport, considering that's exactly where we're building... what are you talking about?
I think he's saying that because he lives more north (rural Redmond), it's quicker for him to take the 520 in a SOV.
Brad, you could always take the 545 to downtown and then get on the link to the airport or take a feeder bus to the closest light rail station and get to downtown or the airport and save loads on gas or parking. Maybe in 12 years from now you'll end up moving closer to a light rail stop, who knows?
Those in Ballard, Queen Anne, Belltown and other Seattle neighborhoods are going to have to take a bus to light rail, too. Of course, bus access in the city is much easier/closer.
Brad, do you commute into downtown, or just go in on weekends? Once 520 is replaced, it will be cheaper for you to park in Redmond and take the train into downtown than it will be for you to pay the 520 toll.
Rizz- Thanks for saying it out loud.
I AM NOT MOVING. Period.
Most of you guys sit at your computers, dreamily pondering the day when all of the people in the suburbs will "get it" and tear down our homes and move to TOD near a PnR.
And you are entirely wrong.
No wonder there is such a huge disconnect on transit issues in this region. It's your way or the highway, right? (pun intended)
Rizzz- Also, the 545 is a joke if you don't work at Microsoft. It's routing is insane for an express bus.
Ditto the 554.
But you knew that already.
Brad... what are you complaining about? You seem to be lashing out, not suggesting anything or being constructive.
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