Sound Transit’s East Link light rail construction is underway, and the Mercer Island station is taking shape. But one of the questions left to be answered is the way the future system, opening in 2023, will connect with existing bus transit.
Islanders have a chance to weigh in on a proposed transit interchange project (also known as “bus/rail integration”). The Mercer Island City Council held a study session with Sound Transit at its March 19 meeting, after the Reporter’s print deadline, but residents can still submit questions or comments at the city’s public engagement website Let’s Talk Mercer Island, which also will contain an FAQ page. The portal opened on March 14.
Sound Transit and Metro plans have called for most of the regional buses from the Eastside to terminate at the South Bellevue and Mercer Island Park and Ride facilities. They will transfer passengers to and from light rail, which will serve Seattle, therefore eliminating redundant service across the Interstate 90 bridge.
That means the buses will have to turn around somewhere on Mercer Island, but the exact location has been under debate for years.
In July 2014, Sound Transit presented a report showing four possible routes for a bus turnaround, with a few going through the Town Center. A plan was later developed to use 80th Avenue Southeast, at the east end of the light rail station.
Islanders were initially wary of the “bus intercept” concept, expressing concerns about diesel idling and regional bus circulation through their downtown. They also wanted to limit future bus volumes to no greater than existing volumes. The council sent a letter to Sound Transit in May 2015 formally rejecting the proposal on the table at that time, and the design was paused.
In 2017, after months of negotiations and litigation on bus-rail integration and many other topics, Sound Transit and Mercer Island reached a settlement agreement that was “intended to offset the impacts of light rail construction and operation, and also to partially compensate for permanent impacts to local traffic patterns,” according to the city.
One of the main objectives of the settlement was to ensure that Sound Transit did not construct its preferred alternative configuration for the bus turnaround on 80th Avenue Southeast. The council preferred a location at 77th Avenue Southeast, to integrate better with the Park and Ride.
The city envisions that westbound buses exiting I-90 from the HOV off-ramp onto northbound 80th Avenue Southeast will take a left (westbound) on North Mercer Way and drop off customers at the existing bus stop of the north side of North Mercer Way. Buses then will make a 180-degree turn at a proposed roundabout at 77th Avenue Southeast, and travel back east to pick up customers at the bus stop on the south side of the street, before getting back on I-90 to return to the Eastside.
The roundabout will result in private property impacts to adjecent homes. Per the settlement, Sound Transit will manage the entire process to acquire the property necessary for the roundabout and “will engage with the property owners using equitable treatment as required by federal and state law.”
King County Metro was not a party to the agreement, but it was known at the time that Metro would need to be involved in implementing the 77th Avenue Southeast configuration. Sound Transit commissioned the “Mercer Island Transit Interchange Operational and Configuration Study” to evaluate how Metro buses will integrate with the light rail station.
The study includes three options: a “limited service configuration,” an “improved service configuration” and an “optimal service configuration,” which adds a preferred pick-up/drop-off stop for local bus service along southbound 80th Avenue Southeast.
Metro would not be able to provide adequate local Mercer Island bus service with the “limited” configuration, according to the study, resulting in loss of service to the current 150 to 175 daily bus passenger trips between Mercer Island and Eastside communities.
Today, there are more than 30 buses per hour serving Mercer Island from off-Island locations during peak commuter periods. The buses start or end their routes in Seattle and include a stop at the Mercer Island Park and Ride. Bus volumes from off-Island locations will decrease to about 20 buses per hour during peak commuter periods when East Link light rail opens and buses no longer stop on the way to or from Seattle.
In 2021, roughly 18-24 months before East Link opens, Metro will lead a public engagement and planning process that will give Mercer Island the opportunity to provide input and feedback on transit services and routing for 2023. The process will guide Metro’s decisions about transit service for Eastside cities not served by light rail and local service including Route 204, Route 630, and other transit and mobility services on Mercer Island.