Shuttle buses will replace 2 Line light rail trains between South Bellevue and Seattle's International District/Chinatown Station all day Oct. 17 and Oct. 18.

Sound Transit announced Oct. 2 that buses will substitute for trains while crews perform planned maintenance on the overhead power system inside the Mercer Island tunnel. The agency said the work is meant to strengthen system reliability and improve service.

The shutdown covers the Crosslake Connection, the seven-mile segment that carries trains across the Interstate 90 floating bridge. Stations at Judkins Park and Mercer Island will also lose train service during the two-day window.

No Route 550 fallback

The Route 550 is gone. Sound Transit discontinued the express bus between Bellevue and Seattle on Aug. 29, directing riders to the 2 Line as the replacement cross-lake connection, as reported by DowntownBellevue.com. The 2 Line is now the only direct transit link between the two cities.

Sound Transit spokesperson Henry Bendon said in August, when the Route 550 was retired, that the shift reflected "a landmark change in how people will get around the region," KING 5 reported.

What riders should expect

Sound Transit's Oct. 2 notice did not specify shuttle bus frequency or estimated added travel time for the Oct. 17-18 disruption. A comparable all-day Crosslake shutdown on July 26 saw shuttles running every 10 to 15 minutes, according to Northwest Asian Weekly.

A separate late-night maintenance window in late July added roughly 30 minutes of travel time when buses replaced trains.

Normal 2 Line service runs approximately 5 a.m. to midnight, with trains arriving every eight minutes at peak times and every 10 to 15 minutes off-peak.

The Crosslake Connection opened March 28 as the first rail link across Lake Washington. The Oct. 17-18 maintenance marks at least the third planned Crosslake shutdown since then.

How to stay informed

Riders can sign up for automatic email service alerts at Sound Transit's service alerts page.

Sound Transit also has a separate, overnight-only disruption scheduled Oct. 6 through Oct. 8, when buses will replace 1 Line and 2 Line trains between Westlake and Northgate stations from 11 p.m. to 4 a.m. That work does not affect the Bellevue segment.