Mercer Island Transit Interchange

Mercer Island Station is an important part of the East Link light rail system.  Metro has already planned to completely fill the capacity for bus transfers at South Bellevue Station and cannot plan for additional routes there. Additionally, direct service to Mercer Island avoids out-of-direction travel for Issaquah/Eastside buses, and provides safer, quicker connections to/from the I-90 HOV lanes, resulting in faster bus travel times and discouraging Eastside drivers from parking on Mercer Island to reach Link light rail.

The 77th Avenue SE Configuration as approved in the Sound Transit Settlement Agreement includes the construction of a new roundabout at the intersection of 77th Avenue SE and North Mercer Way, replacing the current three-way junction (or T-intersection) at this location. The roundabout construction will require Sound Transit to acquire two private properties to the north of the roundabout. Learn more about its property purchasing policies and procedures.

1.  What are the neighboring houses going to see--what is it going to look like from the neighborhood side--once the roundabout is constructed?

The transit interchange is still in the early design stage and the design of the interface between the proposed roundabout and the neighborhood to the north has not been determined. For reference, the houses adjacent to the North Mercer Way and 77th Ave intersection are much closer today than any house will be to the future roundabout.

Although the existing shrub hedges in the landscaped areas north of the North Mercer Way/77th Ave SE intersection would likely be removed for construction activities and revised ADA compliant trail connections, new landscaping and fencing will replace those removed. Sound Transit intends to work closely with the City of Mercer Island as the design progresses to provide appropriate buffers and screening between the roundabout/transit interchange and the neighborhood to the north.

2.  Is the current pedestrian cut-through going to remain?

The proposed transit interchange is still in the early stages of design and connections to the adjacent neighborhood have not been fully designed at this point. However, the conceptual plan envisions a connection of some sort between the I-90 Trail and the north neighborhood at least to the same scope of what exists today.

3.  What is the planned use for the remainder of the two lots and what will they look like? (I'm talking about the lots where the two houses are--the houses that will be torn down)

Plans for the property not disposed to the City of Mercer Island for the roundabout are unknown at this time (Sound Transit to retain ownership of this remaining property). However, per the conceptual design, new roadway features will allow for a number of additional landscaped areas; the entire north side of the roundabout will have an approximately 5-foot planter, allowing for the installation of new (or existing) trees/shrubs to separate the I-90 Trail and the proposed roundabout from the neighborhood to the north. Sound Transit intends to work closely with the City of Mercer Island on redevelopment that is compliant with local zoning codes and development plans.

4.  What will be done to reduce the impacts (sights, smells, sounds) of the roundabout and increased traffic?

The proposed roundabout will not result in an increase in traffic; in fact, the total number of buses on Mercer Island will not exceed existing numbers and will be reduced by almost half due to the Settlement Agreement. The proposed roundabout was analyzed during the environmental review process.

5.  Will there be a sound wall and/or replacement landscaping? Assuming there is a sound wall, where will it be in relation to the two lots?

The transit interchange is still in the early design stage and no decisions have been determined at this time. Sound Transit intends to work closely with the City of Mercer Island as the design progresses to provide appropriate buffers and screening between the roundabout/transit interchange and the neighborhood to the north.

6.  How many buses will be laying over during the afternoon peak period? Where will they be laying over? --Please confirm that there are no plans to use part of the two lots as a bus parking or layover area.

The exact number of buses laying over during the afternoon peak are not known at this time. Metro will be updating its service plan for this area much closer to the start date of East Link revenue service in 2023. Per the proposed configuration, buses will lay over on both the north and south sides of North Mercer Way to the east of the proposed roundabout; the amount of curb space available for buses would allow up to 4 buses laying over at any given time. There are no plans to use the two lots for additional bus layover or bus parking areas.

1.  Why can't Sound Transit construct their own bus right-of-way "dedicated bus ramps" so that they do not have to use any Mercer Island Streets?

The transit interchange is being constructed as approved by the 2017 SEPA Addendum to the East Link Final Environmental Impact Statement (FEIS) as modified by the Settlement Agreement between Sound Transit and City of Mercer Island.  There is currently a parking restriction in place for all of I-90 in this area and WSDOT would not be supportive of using ramp shoulders as bus waiting areas adjacent to traffic. Freeway on- and off-ramps are within limited access right of way and provide a critical acceleration/deceleration pathway for vehicles entering the freeway. They are designed to allow for safe acceleration/deceleration, visibility, and are not appropriate bus layover locations.

2.  NMW is the only SOV on-ramp for I-90 from ICW. Won't the new design stop traffic from being able to enter I-90 Westbound even more than it is congested now?

The proposed transit interchange will not restrict access to I-90 or result in an increase in congestion. The roundabout at 77th Avenue SE will be an efficient means for SOV traffic to enter the on ramp at 76th Avenue SE.  The number of buses will be roughly fifty percent of today’s volumes.

3.  Why can't overpasses be constructed for pedestrian and bike traffic that will interrupt vehicle traffic?

While some wish we could separate roads for bikes, pedestrians and cars, the cost would be a prohibitive use of public resources. In addition, the connections for Mercer Island businesses for people to pass their doors would be limited. In this particular instance, the cost of building additional overpasses to FHWA and WSDOT specifications would be cost prohibitive for a use of public resources. The transit interchange is being constructed as approved by the 2017 SEPA Addendum to the East Link Final Environmental Impact Statement (FEIS) as modified by the Settlement Agreement between Sound Transit and City of Mercer Island.

1.  What are the benefits to Mercer Island residents from the "optimal service configuration"?

The transit interchange will serve to enhance Mercer Island and Eastside service and compliment the new light rail network. It will connect Mercer Island to Eastside communities not served by East Link, including Issaquah, North Bend, and Sammamish. Specifically for Mercer Island, this service will aim to reduce vehicle trips and parking demand from the Eastside on Mercer Island streets and public parking facilities. The transit interchange will also connect light rail to residents, jobs and services on Mercer Island.

2.  Does the current settlement agreement with ST limit buses using the bus intercept to 12 per hour, and does the "optimal service configuration" increase the number of buses per hour to 20?

The Settlement Agreement limits buses to roughly today’s number of 34 during the AM peak, 34 during the PM peak, and 346 daily. The optimal service configuration will result in an almost 50 percent reduction from today’s total buses during these peak periods.

3.  If the "optimal service configuration" allows 20 buses per hour, and each bus can lay over for up to 20 minutes per METRO's union contracts for driver breaks, and there are four bus parking bays, two on each side of North Mercer Way, does that mean two buses will be parked on each side of NMW all day long? How long will these buses be?

The optimal service configuration will include one (1) layover space on the north side of North Mercer Way and three (3) layover spaces on the south side of North Mercer Way. It is anticipated that these layover spaces would be utilized to the greatest extent during the AM and PM peak periods, and to a lesser extent during other periods. It is not expected that layover spaces would be fully occupied all day long. On average, buses will be in layover spaces for approximately 15 minutes. Metro has a financial and operational incentive to reduce layover time as much as possible.

In 2021, roughly 18-24 months before East Link opens, Metro will lead an extensive public engagement and planning process to give Mercer Island residents the opportunity to provide input and feedback on transit services and routing when East Link opens. While service levels are not known at this time, it is anticipated that service will take the form of a mix of 45-foot buses, 60-foot buses, and DART vehicles.

4.  Is there any expiration date in the future should the city agree to the "optimal service configuration" or is it forever once the city agrees?

There are no expiration dates associated with the bus/rail integration section of the Settlement Agreement.  The amount of proposed service configuration already limits transit service below what was planned for in Metro Connects, King County Metro’s long-range plan.

5.  How many trees will have to be removed as part of the "optimal service configuration" including for the roundabout at 77th and NMW?

The transit interchange will result in the removal of five trees on the north side of North Mercer Way, for the proposed bus layover space. Depending on existing tree/root health, some/all trees could be salvaged and moved within the project area to keep aesthetics and continuity within landscaped areas. Importantly, the proposed roundabout is expected to retain many trees in the project area, including nearly all the trees to the west of 77th Avenue SE and all trees along both north and south sides of N Mercer Way in existing bus pick-up/drop-off areas adjacent to 80th Avenue SE.

In addition, revisions to the proposed sidewalk and roadway alignment going into the roundabout will maintain a full row of secondary existing trees and shrubs (behind the existing sidewalk), providing separation from transit facilities, sidewalk and roadway from the I-90 corridor. It is anticipated that new street trees and additional landscaping will be included along North Mercer Way and 80th Avenue SE as the design moves forward.

6.  Who is negotiating on behalf of the city of Mercer Island, and when did the negotiations begin?

The Settlement Agreement between Sound Transit and the City of Mercer Island was executed in November 2017. City staff have been working with Sound Transit to implement the Settlement Agreement, but the Settlement Agreement has not been re-opened for negotiations.

7.  The city is hiring outside experts to negotiate the MOU for the Tully's project. Why isn't the city hiring an outside expert to negotiate the "optimal service configuration", especially considering the city's poor results in negotiating the settlement agreement with ST?

The City of Mercer Island is working hard to make sure Mercer Island residents get clear information from KC Metro and Sound Transit about how this configuration will benefit Mercer Island residents and businesses.  All three parties, plus WSDOT, are working collaboratively on the final design of the transit interchange.  The Executive Summary of the Transit Interchange Studydescribes how the optimal configuration meets the goals of Mercer Island.

8.  How much money for mitigation is ST or METRO offering for the "optimal service configuration", and if they are not offering any money why not?

Per the Settlement Agreement, Sound Transit will authorize payment to the City of Mercer Island up to approximately $10Million for a number of transportation-related projects, not including the total cost to design, construct, and implement bus/rail integration on Mercer Island. Mercer Island residents and businesses are also a receiving a light rail station with all its connections to the region.  King County Metro was not a signatory to the Settlement Agreement. The transit interchange does not require mitigation per the 2017 SEPA Addendum to the East Link Final Environmental Impact Statement (FEIS).

Updated information from Sound Transit (we apologize for any confusion):

The ventilation shafts on the head houses are functional as they provide passive cooling for the buildings and circulate airflow. At one of the public meetings on Mercer Island, the color was shown as a brighter red (Ferrari Red) with gray as an alternate, which are both within Sound Transit’s standard family of colors.

Sound Transit heard comments that this red was too bright and proposed an earth tone/terracotta orange – this will be the color when the station is complete. If you walk by the station today, the ventilator shafts are covered in a bright orange waterproofing material that will be covered up and then painted with the terracotta color.

[Prior Answer -- The “smokestack” objects on the headhouses (air vents) are currently under construction and have not been completed.  They will be slate gray when finished.]

From Sound Transit: To access South Bellevue, Metro customers would have to travel off I-90 onto Bellevue Way, north to the station, and then board Link rail and backtrack along Bellevue Way to I-90. In the eastbound direction, the merge from Bellevue Way to I-90 is extremely congested and presents safety and operational challenges for buses merging across several lanes to get from Bellevue Way into the center HOV lane. This travel time, assuming a 5-minute light rail trip from South Bellevue to Mercer Island, is 10 minutes longer in each direction during peak travel periods than traveling directly from Eastgate to Mercer Island.

In addition, direct service to Mercer Island avoids out-of-direction travel and provides safer, quicker connections to/from the I-90 HOV lanes, resulting in faster bus travel times and discouraging Eastside drivers from parking on Mercer Island to reach Link light rail. Finally, Metro has already planned to completely fill the capacity for bus transfers at the South Bellevue Station and cannot plan for additional routes there.

From the Mercer Island Police Chief: The Park & Ride area currently sees approximately 30 buses per hour during peak commute times and our Police Dept already works closely with Metro and Sound Transit to respond to any criminal or disruptive behavior related to bus riders. We will continue to work with our partners when dealing with potential issues that may be created in the future by light rail users. In addition, as the opening of the light rail station approaches, the MIPD will begin training with the Sound Transit officers to prepare for security operations and possible impacts to our community. 

While we expect bus volumes to decrease with the advent of light rail, we understand that we may see an increase in overall transit users when light rail is up and running. The MIPD has consulted with other law enforcement agencies that have rail transit stations in their cities and have been advised that cities located at the end of rail routes have more challenges than cities in which rail transit passes through.  Although the Mercer Island station is not located at the end of a transit line, we remain mindful of the potential for criminal behaviors associated with light rail.  We all want the users of East Link light rail to enjoy a safe commuting environment and will work with our citizens and public safety partners to keep our Island both a safe and welcoming community. 

1) The roundabout is required to allow I-90 westbound buses to enter Mercer Island, drop off passengers at the Park & Ride, turn around, and then return to I-90 eastbound without circulating through the Town Center. These buses could not turn around at the existing intersection with a traffic light.

2) Studies show that travel times are improved with a roundabout versus a signalized intersection.

3) There is no intention to change local driving patterns with the construction of the roundabout. 

Thank you for your suggestion; we will forward to the design team.

There will not be public restrooms, but drivers will continue to have access to a non-public restroom that is already in service at the Park & Ride.

The existing Mountains-to-Sound (aka I-90) Trail will be routed around the north side of the roundabout. But the North Mercer Way & 77th Ave SE roundabout is still at 30% conceptual design, so the exact path width has not yet been finalized. WSDOT requires a minimum 10-foot wide path with two 2-foot shoulders (total of 14 feet), so this design would allow for the WSDOT minimum.  The final roundabout design will incorporate Aubrey Davis Park Master Plan requirements once the Plan has been approved by City Council later this year. 

The North Mercer Way & 77th Ave SE Roundabout is at 30% conceptual design, so does not yet show this level of detail.  Safety is the top priority for Sound Transit, as well as the City, so the pedestrian crossing and area's lighting will be carefully designed by ST and closely reviewed by City engineers as the design is further developed.

There are currently 36 AM and 39 PM peak-hour bus trips.  The Settlement Agreement requires that when East Link opens in 2023 there will be no more buses than today.  The Optimal Service Configuration would expect up to 20 AM and 20 PM peak hour bus trips.

Thanks - these would be both be Sound Transit's decision, so we've forwarded to them for an answer.

Info from Sound Transit: 

Plans do not include weather protection for the sidewalks along N. Mercer Way or 80th Ave, however, there is some weather protection provided on the station platform and within the headhouses on 77th Ave SE and 80th Ave SE.  Street lighting will remain, and there will be adequate lighting at the station entrances. The traffic signal timing will be re-evaluated with WSDOT involvement closer to the time that the light rail station and bus/rail integration is operational.