Sound Transit's commuter-rail service turns 15

Sound Transit last week marked the 15-year anniversary of its Sounder commuter-rail service.

The agency began operating two south line roundtrip commuter trains in September 2000, with stops in Seattle, Tacoma, Sumner and Auburn, Wash. Service was added to the Puyallup and Kent stations in February 2001 and to Tukwila a month later.

North line service to Edmonds and Everett, Wash., began in 2003. Sound Transit added service to Mukilteo in 2008.

Sounder trains have carried more than 29 million people over the past 15 years, Sound Transit officials said in a press release.

Ridership has continued to grow along the Puget Sound-area commuter-rail system, which in July logged more than 2.1 million rides year-to-date. That figure marked a 14.7 percent increase from the same period last year.

Also in July, average weekday boardings climbed to 14,804, marking a 15.3 percent year-over-year jump.

As a result of voter-approved service expansions, the 10 daily round trips along the Sounder south line will increase to 13 each weekday by 2017. Four round trips each weekday currently travel on the north line, where rider demand is lower and costs for accessing BNSF Railway Co. are higher, Sound Transit officials said.