The King County Department of Metropolitan Services (Metro) and the regional transit agency, Sound Transit, provide public transportation services for Mercer Island and throughout King County. There are four major types of service offered on the Island: local fixed route service, regional express service, custom bus service, and Access service.
Local fixed route service operates on the arterial roadway system, and provides public transit service connecting residential and activity areas.
Regional express service, which also operates on fixed routes, is oriented toward peak hour commuter trips between the Mercer Island Park and Ride and major employment and activity centers off the Island. Sound Transit and Metro provide express service west and east along I-90 into Seattle and Bellevue.
Custom bus service includes specially designed routes to serve specific travel markets, such as major employers, private schools, or other special destinations. These services are typically provided during peak commute hours, and operate on fixed routes with limited stops. Custom bus service is currently provided between the Mercer Island Park and Ride and Lakeside School and University Prep in Seattle.
Access service provides door-to-door transportation to elderly and special needs populations who have limited ability to use public transit. Access covers trips within the King County Metro transit service area.
Figure 6 shows the current transit routes serving the Island. On Mercer Island, there are two routes that circulate throughout the city (Metro routes 204 and 630). At the Mercer Island Park and Ride, Sound Transit routes 550 and 554 connect Mercer Island to Seattle, Bellevue, and Issaquah; and Metro route 216 provides service to Redmond and Seattle.
Route 204 provides service between the Mercer Island Park and Ride lot and the Mercer Village Center. This route travels on 78th Avenue SE, SE 40th Street, 86th Avenue SE, Island Crest Way, and SE 68th Street to the Mercer Village Center. The route operates every 30-60 minutes from approximately 6:00 AM to 7:00 PM on weekdays. Metro plans to increase this route’s service frequency in 2019, including additional service on Saturdays.
Route 630 is a community shuttle which provides service between downtown Seattle and the Mercer Village Center. It provides five trips toward downtown Seattle in the morning and five trips toward Mercer Village in the evening.