Sound Transit and King County Metro provided an update to the Mercer Island City Council on East Link’s construction progress on Tuesday, March 19.  The presentation also included information about the future Mercer Island Transit Interchange, which is the new name for the project formerly known colloquially as the bus intercept.

The general concept remains generally similar as previously reported, but at this time Sound Transit and Metro, in coordination with the City of Mercer Island, have made some refinements and identified options for Mercer Island to consider.

The Settlement Agreement which ended East Link-related litigation in 2017 abandoned the previous 80th Ave SE concept and instead mandated the roundabout at the intersection of 77th Ave SE and N Mercer Way to allow buses to turn around; required all regional bus drop-off, layover, and pickup to occur on the south side of N Mercer Way; and limited layovers to no more than 15 minutes, and only in the PM peak period.  A diagram of the concept is shown below.

Under the Settlement Agreement, buses would exit the westbound I-90 HOV direct access ramp (1), circulate through the roundabout (yellow circle), then drop off passengers and layover (4) before picking up passengers at the existing eastbound bus bay (5) before re-entering I-90 via the eastbound HOV direct access ramp (6).

Metro expressed concerns about how the various provisions would limit future regional bus service and impact the implementation of Metro Connects.  Metro and Sound Transit staff developed proposed changes to the physical configuration and to operations that would increase the number of buses that could use Mercer Island Station. Specifically, Metro requested the ability to drop off passengers earlier (2) to both facilitate quicker access to the station and improve the utility of the layover spaces, the use of layovers throughout the day instead of only during the PM peak, and the addition of more layover space (3). They also suggested the potential addition of an in-lane stop southbound on 80th Ave SE to serve Mercer Island local bus routes (7).

Metro and Sound Transit commissioned a report that analyzes various configurations to determine their ability to support bus service. The report estimates that infrastructure and operations consistent with the Settlement Agreement (the “Limited Service Configuration”) could support approximately 12 buses per hour, due to complications with bus movements for drop-off, layover, and pickup.  Allowing passenger drop-offs at the existing westbound bus bay (the “Improved Service Configuration”) could support up to 16 buses per hour by improving ability to access layover areas, while the additional layover space described above (the “Optimal Service Configuration”) could support up to 20 buses per hour.

In response to questions from the Mercer Island City Council about South Bellevue, Katie Chalmers, Service Planning Supervisor for Metro, explained that South Bellevue Station’s bus layover capacity is already maximized with other bus service including I-90 express routes coming up I-405.  In addition, buses already in the I-90 corridor coming from Eastgate, Issaquah, or Sammamish find it approximately 10 minutes faster to travel to Mercer Island compared to South Bellevue due to the HOV direct access ramps at Mercer Island and the distance of the South Bellevue Station from I-90.  As Metro’s intention is to not run any service across I-90 to Seattle once East Link opens, without Mercer Island, Metro would likely have to send buses to Bellevue Transit Center instead.

Metro has not identified a specific service pattern for I-90 service at this point, and won’t begin this process until 2021, two years before East Link opens. The general concept is to provide service to at least the same destinations as today (Eastgate, Issaquah, Sammamish) and reinvest service hours presently spent getting to and through downtown Seattle back into service on the Eastside. This could lead to improved service frequency, more destinations, or a combination of both.

In response to questions about train capacity Sound Transit’s Mike Bell, Executive Project Director for East Link, and Luke Lamon, Government and Community Relations, noted that peak headways are anticipated to be every 6 minutes (author’s note: 6 minute peak headways may be referring to ST3 buildout and not the anticipated ST2 service plan, which is for 8 minute peak headways) using 4-car trains, which can carry approximately 600-800 passengers depending on how tightly people are willing to squeeze onto trains.  Katie Chalmers noted that peak bus ridership on Metro’s service in the I-90 corridor (e.g. excluding the 550 and 554) is between 6-7,000 per day, which is easily accommodated by East Link.

The Mercer Island City Council had additional questions and concerns about project impacts, especially to the residential neighborhood north of N Mercer Way, and also about non-motorized station access and safety at the future roundabout at 77th Ave SE/N Mercer Way and at the 80th Ave SE/N Mercer Way intersection.  The Mountains to Sound Trail runs along N Mercer Way in this area and is a heavily used bike route.  Sound Transit recently made improvements at the Mercer Island Park and Ride to reduce pedestrian/bicycle conflicts, and is considering pedestrian and bike safety as the roundabout advances through design.

No decisions were made, although Sound Transit indicated it needs a decision soon as construction of the roundabout and other improvements would start in late 2020 to be complete in late 2022 before East Link opens.

You can find more documents on Mercer Island’s project page, and watch the video of the presentation on YouTube.

30 Replies to “Transit Integration at Mercer Island”

  1. A 10-minute penalty for reaching downtown by switching to Link at South Bellevue P&R vs. Mercer Island feels excessive. I suppose it is 10 minutes if one’s ultimate destination is actually Mercer Island (since you also have to wait for the train). But, if you’re trying to get to DT Seattle, you’d have to wait for the train anyway, so the difference is really just the driving up and down 1/4 mile along Bellevue Way, so maybe 2 additional minutes at most.

    1. Yeah I’d agree. Plus, South Bellevue would be shorter for those heading to Downtown Bellevue or the Spring Dustrict than Mercer Island would be.

    2. A couple years ago I figured that going to Mercer Island was a wash westbound and about 2 minutes faster eastbound for buses in the I-90 corridor compared to South Bellevue, but there are operational and safety considerations in play too. Traffic has also gotten worse and is likely to continue to get worse by the time East Link opens, so while 10 minutes may be on the high end of a reasonable range I’m inclined to believe Metro when they say that Mercer Island is faster.

      Metro also mentioned wanting to avoid out-of-direction travel to the extent possible.

      1. “safety consideration” = to get from Eastgate to S Bellevue, bus has to merge across 4 lanes of traffic in a relatively short time frame, while moving with traffic that is over going 60+. It’s not as hard as the Mercer Ave to SR520 weave (which Metro & ST refuse to do), but it’s pretty hard.

      2. Per google maps, it is 0.7 miles from the end of the double white lines at the Eastgate HOV on-ramp to the start of the solid white line for the Bellevue Way exit only lane. The bus will already be in the HOV lane regardless, but to get to Bellevue way it needs to cross 2 general purpose through lanes and then enter the exit only lane.

        So that is 3 merges in 0.7 miles.

      3. They would get off the freeway at the free way HOV on and off ramp head down behind the park and ride down Eastgate way and on to the freeway were the would get off at the Bellevue way off ramp. It would be an additional two lights and and an all way stop by Bellevue college. so yeah 10 minuts

    3. “you also have to wait for the train” – but taking the bus to S Bellevue would mean you catch an entirely different train than the one at MI. If you immediately catch the train in MI vs narrowly miss the next train in S Bellevue it could be a 12 minute penalty. So let’s just call it 10 minutes.

      Bellevue Way is at complete gridlock during rush hour, particularly the ramp for to I90E, because traffic needs to weave through the Factoria exit and that traffic typically backs up into the GP lanes in the afternoon. A 10 minute penalty to get both to and from S Bellevue, relative to an HOV lane that is generally free following between Eastgate and MI, seems optimistic to me.

      During the afternoon commute, I’d argue it will be faster to transfer at MI even for people heading to/from Bellevue.

    4. When I was in high school i took a bus from Somerset to Mercer Island and transferred to an opposite-direction bus to Bellevue HS. The transfer wait for that particular run was 10 minutes, so comparable to Link.It was not bad, and much better than the alternatives. It may seem out of the way to go to Mercer Island, but it’s not that much overhead.

    5. buses already in the I-90 corridor coming from Eastgate, Issaquah, or Sammamish find it approximately 10 minutes faster to travel to Mercer Island compared to South Bellevue

      I interpret that sentence to mean that it is the time it takes for a bus to get to a station. Thus the time spent on a train or the frequency of the train is irrelevant to the statement. What is ambiguous is whether that it round trip or not. My guess is that it is round trip, since 10 minutes one way does seem excessive. I’m sure one of the big issues is when to leave the HOV lanes. In the case of Mercer Island, as they said, you never do. You are basically door to door in the HOV lane. In the case of South Bellevue, you have to move over three lanes, which can take a while. There is also a traffic light on 112th. While a bus may turn right before then (it isn’t clear to me whether it will or not) it will certainly be slowed by traffic that backs up (I don’t think there will be HOV lanes on Bellevue Way).

  2. A compromise service pattern might be to run the 21X series to MI, as those are the express routes to Seattle and do much of the heavy lifting at peak, and then run the 554 to South Bellevue. The 554 is intended to be build ridership for the future Bellevue-Issaquah line, plus the 554 is all-day and the penalty of going to S Bellevue over MI is significantly less outside of rush hour, whereas the 21X are generally peak-only.

    1. Metro wouldn’t talk about specific potential service patterns, but based on prior discussions that seems to be the likely outcome. ST is strongly considering rerouting the 554 to Bellevue TC after East Link opens, and Metro clearly wants to run all their I-90 corridor service to Mercer Island if possible. I-405 service that goes across I-90 (111 & 114) seems destined for South Bellevue.

      1. That makes a lot of sense (I was thinking the same thing). While it would be great to have a central transit hub for the area, the various agencies and communities don’t want that. Mercer Island doesn’t want that, and South Bellevue can’t handle the load (and has local traffic issues). So splitting service is the way to go. Sending I-90 buses to Mercer Island means the bus is the HOV lane the entire time. Buses from I-405 (south of I-90) can’t do that, so you might as well send them to South Bellevue.

        The irony is that there is a flyover ramp that connects I-90 to I-405, but it is for the wrong section. Express buses can go from Bellevue to Mercer Island really easily, but I just don’t see any of them doing that once East Link opens.

      2. Why wouldn’t the 111 just head to Bellevue TC? Is the thought that the route would never use the 405 HOT lanes (since it’s serving stops like Newport Hills P&R), so i’ts better off staying on the right and following the off ramp to Bellevue TC? Any bus in the 405 HOT lanes would surely head to Bellevue TC, right?

        I feel like the 111/114 would be better re-thought as feeder routes that connects to 405 BRT at 44th, and a different route(s) would take care of Newport Hills.

  3. I’ve sometimes toyed with the idea of having at least one Eastside route ending at Mercer Island instead continue on the I-90 bridge to end in Seattle. It could provide connectivity if East Link has an inevitable occasional operations problem.

    A through-routed bus could also provide direct connections between the entire Eastside and First Hill medical facilities. Rather than ride an I-90 bus, ride Link all the way into Downtown and then transfer again to take a bus up First Hill (AKA double transfer as opposed to today’s single transfer), a rider could make the trip on just one vehicle without transferring.

    1. I like that idea. They could have a stop on Mercer Island, then get off at Rainier, serve first hill, then head straight up Boren Avenue to SLU.

      The question with that is after East Link, whether M.I. will continue to allow buses stopping on the island and continuing like the 550 and 554 do today.

      1. Just so you know, Mercer Islanders have no say in the matter. It is Sound Transit and Metro who are dictating what they are going to do and who are taking away our choices of allowing buses to go all the way to Seattle from the Eastside. Plus, Sound Transit don’t want Mercer Islanders to have a choice like the Redmond Technology Center who already have Rapid Bus Transit, as well as the regular buses. They want to force bus riders off the buses at the Mercer Island Park and Ride, traipse across the road and down to the light rail stations which will add another 5 minutes more to the trip, so if you take the first leg from Issaquah, for example, then add the trudge from the bus stop to the light rail station, the wait for the next train, which ST and Metro now say will be every six minutes which is ridiculous, it won’t be quicker by bus and light rail, it would be quicker if they just put Rapid Bus Transit buses on from Issaquah all the way to Seattle, but they won’t put those on.

    2. I think, in practice, riders would spend more time sitting in traffic than what they’d actually save by not having to transfer. The last leg, many could avoid the transfer anyway by walking up the hill from downtown.

      Traditionally, Metro scheduled their routes with the premise that avoiding transfers was an end in itself, independent of the actual time saved, but that way of thinking leads to a ton of service hours being spend providing one seat rides to whichever institution demands them the loudest, and leaves the public, as a whole, worse off.

      It is better to spend the hours to just run Link, and the Link connector buses as often as possible.

      1. System disruptions can occur any time of day, so congestion concerns are not a sufficient reason to discount the concept.

        Further, double transfers require lots of waiting during non-congestion periods. This route concept would likely be more beneficial at noon or at 8 PM than at 8 AM or 5 PM.

      2. At noon, you don’t have the ridership to justify the service hours. At best you’re each service hour is saving maybe 10 minutes for 10 riders. It’s better to spend the money running the regular buses more often.

    3. I don’t know about downtown Seattle, but what about West Seattle, Leschi or Madrona? West Seattle and Central District residents could transfer at Mercer Island to get to Bellevue and westbound passsenergs could transfer to the 2 or 3 to get to some places on Capitol Hill.

      1. I’ve got no particular route in mind. I suggested First Hill because it’s closer to I-90, is a major regional destination for workers and visitors, and only connects to the Eastside by transferring in Downtown Seattle (no First Hill-Judkins Park routes exist except the infrequent 9X). Certainly a route could connect other areas.

        Scenario: East Link must close at the Lake Washington bridge at any time of day or day ok week. A bus bridge is needed. If just one route goes on I-90, the signs explaining what to do and where to wait (bus stops) are already set up! ST/Metro may be able to address the crisis by merely saying “wait for the next 212” and assign additional, emergency runs to it ( as opposed to instantly implement a new route with new stops for only a few hours).

      2. Since a floating bridge closure is reasonably likely to occur (about once every 10 years due to weather IIRC, plus Seafair/Blue Angels closures), I would imagine ST and KCM would have something similar to Route 97 ready to implement if/when needed.

        If the floating bridge is still open to auto traffic, then you’d probably do a bus bridge between Mercer Island and IDS (I-90 ramp configuration at Rainier makes a connection to Judkins Park problematic; it works well westbound but doesn’t work eastbound) and possibly send all the I-90 buses that would otherwise terminate the Mercer Island across to IDS.

        If the floating bridge is totally closed you might want to run the bus bridge between Bellevue TC and UW instead. That way you’d have Link passengers transfer at Bellevue TC, and you either redirect the I-90 buses straight to Bellevue TC or just keep running them to Mercer Island and make everyone do a bunch of out-of-direction travel. There aren’t really any great options with the floating bridge totally closed but a Bellevue TC-UW bus bridge at least makes some sense.

      3. About the bus bridge from Bellevue TC and UW, is it really likely that the 520 bridge would remain open when conditions necessitated the closure of the I-90 bridge? That seems far-fetched to me.

      4. ST’s analysis indicated that there are certain north wind conditions that would necessitate stopping rail service over the I-90 floating bridge. However these events wouldn’t cause the entire bridge to close.

        Historically the I-90 bridge has been far less susceptible to weather than the 520 bridge, but with the 520 bridge being new we don’t have a good history to work with anymore. The new 520 bridge is far less susceptible to bad weather than the old bridge due to its design (the pontoons are bigger and stronger, and the bridge deck is elevated above the water).

      5. And I should add that the Blue Angels performances cause several I-90 floating bridge closures in August, which don’t affect 520 beyond screwing up traffic.

      6. Closures would probably occur more as a result of specific operational disruptions to Link than from a closure of the bridge because of high winds. Examples include suicide jumps in front of trains, freak accidental deaths including electrocutions, system computer problems, vehicles with stuck doors, criminal activity on a train that requires police investigation, power substation failures, and the list can go on and on. East Link even has a few at-grade street crossings in Bellevue so occasional auto-train collisions could cause problems.

      7. It sounds like we need more feeders at Judkins Park Station. The 48 takes care of part of the CD, and the 4S could take care of Harborview although Metro plans to delete it. The rest of First Hill would need something on Broadway or Boren.Metro’s 2025 plan has a Frequent route on Boren-MLK, so that would serve the western part of First Hill.

        For Madrona, the 2025 plan has a Local route from Madison & MLK on MLK, Yesler, 23rd, Judkins Park Station, and Beacon Hill Station. In the 2040 plan it’s upgraded to Frequent.

        Leschi has a route north to Yesler-Boren-SLU and south to Mt Baker Station. I assume the residents don’t want to hear about redirecting it to Judkins Park. And Leschi seems too low-population to justify a second route to Judkins Park, so i don’t know what we could do there.

        As for West Seattle to Judkins Park, hmm. I think they’d better transfer to East Link at Intl Dist. It’s nonstop from there to Judkins Park, so Link would be much faster than a bus extension.

        For Capitol Hill to Judkins Park, there will be the aforementioned routes on Boren and 23rd. There could be another route around 12th or 15th. I’ve been a little uncomfortable with the idea of having no route between north Rainier and Broadway (as the 9X does).

    4. Today you can transfer to the 630 at the MI P&R during peak times when the 630 is running. It is a one-way semi-loop via Rainier, Boren, Seneca, and 5th so it provides direct service to First Hill without transferring downtown, although its usefulness to access downtown is limited unless you’re coming from south Mercer Island (and transferring to the 550 is probably faster anyway). The 630 is moving out of “pilot” status soon (or has already), but its continued existence is dependent on City of Mercer Island, City of Seattle, and King County Metro funding.

  4. Recently WSDOT gave a presentation to the Mercer Island City Council on WSDOT’s upcoming $750 million project on 405 from SE 8th street to the I-5 interchange. According to WSDOT the increase in lanes and HOT lanes will eliminate congestion on 405 southbound even during peak times, and there will be only mild congestion northbound on 405 during peak times. Furthermore island bus stops will be installed to allow buses to exit and enter the HOV lane from 405 for off-loading and on-loading which will make it much easier to navigate to the S. Bellevue Park and Ride.

    According to the WSDOT representative it was his understanding the eastside bus intercept would originate at the S. Bellevue Park and Ride, and not Mercer Island.

    My guess is Bellevue has an agreement with ST that the S. Bellevue Park and Ride will not serve as a bus intercept for areas south of 405, and ST is terrified of Bellevue.

    1. Beware DOTs promising to solve congestion with just another lane. The HOT lanes will, in theory, ensure buses will move no slower than 45 mph on 405, which is nice but irrelevant to I90 buses and the MI intercept. Any KCM or ST route on 405 will certainly terminate at the Bellevue TC, not S Bellevue nor MI, unless it’s a local route traveling through Factoria. If a bus is already in the center lane of 405, the best option is to proceed to downtown Bellevue.

      Someone catching the bus in, say, newcastle or north Renton is looking at a transfer to East Link in downtown Bellevue.

      The island bus stops in the 405 Master Plan are being built to support the 405 BRT, which will terminate at Bellevue TC using the existing direct access ramp. None of that infrastructure will help to getting over to South Bellevue.

      The long term WSDOT master plan includes a rebuild of the 405-I90 interchange to have HOV-to-HOV flyover ramps, simillar to what is being built at the SR16-I5 interchange. This rebuild is 1. Unfunded, 2. Would cost $750M by itself, and 3. Is decades away.

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