Sounder commuter rail

Sounder (reporting mark SDRX) is a commuter rail system that serves the Seattle metropolitan area in the U.S. state of Washington. Managed by Sound Transit, it uses 82 miles (132 km) of tracks, primarily owned by operator BNSF Railway, and runs with equipment maintained by Amtrak. Sounder is split into two lines that intersect at King Street Station in Seattle: the N Line to Everett and the S Line to Tacoma and Lakewood.

Trains typically operate during peak periods, with morning trips to Seattle and afternoon trips to outlying suburbs. Limited mid-day service is offered on the S Line, and both lines offer special weekend trips for sporting events and other major events. Sounder has 12 stations that connect with Link light rail as well as local and regional bus systems. Most also provide park-and-ride facilities, bicycle lockers, and other amenities. Fares are paid using ORCA cards, paper tickets, and mobile ticketing apps, and validated through proof-of-payment checks. In 2024, the system carried a total of 1.9 million passengers, or an average of 7,300 on weekdays.

The commuter rail system was preceded by mainline passenger railroad services that began in the late 19th century and two interurban railways that connected Seattle to Everett and Tacoma in the early 20th century. The Municipality of Metropolitan Seattle (now King County Metro) led studies into a modern commuter rail system in the 1980s that were later transferred to the Regional Transit Authority (now Sound Transit), created in 1993. A demonstration service from Everett to Tacoma ran in early 1995, ahead of an unsuccessful ballot measure to fund a regional transit system. A second ballot measure, Sound Move, was passed by voters in November 1996.

Sounder was among the first Sound Transit projects to be launched and construction on its stations began in 1998. The South Line (now the S Line) entered service on September 18, 2000, and was followed by the North Line (now the N Line) on December 26, 2003. Additional trips on both lines were launched in the 2000s after a series of signal and track improvements were completed by Sound Transit and BNSF. The South Line was extended from Tacoma to Lakewood in October 2012 and debuted the first mid-day Sounder trips in 2016. Both lines were rebranded in 2021. An extension of the S Line to DuPont was funded by the Sound Transit 3 package in 2016 and is expected to open in 2045.

The Sounder commuter rail system comprises two lines that total 81.8 miles (131.6 km) in length and serve twelve stations. King Street Station in Downtown Seattle is the system's central hub and the terminus of both lines. The N Line (formerly the North Line) serves three stations and terminates in Everett; the S Line (formerly the South Line) serves eight stations and terminates in Lakewood, with some trips ending in Tacoma. The two lines carried a total of 1.92 million passengers in 2024, of which 99 percent were on the S Line; Sounder was the 13th-busiest commuter rail system in the United States by ridership that year.

Train service is primarily operated during weekday rush hours, with trips inbound to Seattle during the morning and outbound to the suburbs in the afternoon. Other services, including reverse commute and mid-day trips, are offered on the S Line while both lines have occasional weekend service for special events. Most of the Sounder system uses tracks owned by BNSF Railway, which is also contracted to operate the trains. Amtrak provides fleet maintenance and storage of trains at their Seattle facility. The Lakewood–Tacoma segment of the S Line, part of the Point Defiance Bypass, uses tracks that are owned by Sound Transit.

The N Line begins in Seattle and travels north for 34.2 miles (55.0 km) on the BNSF Scenic Subdivision towards Snohomish County, where it serves three stations and terminates in Everett. It typically uses short trainsets with two or three passenger cars during its normal four round-trips on weekdays; for special event services, the N Line has five-car trainsets. Trains leave King Street Station and cross beneath Downtown Seattle in the Great Northern Tunnel. The tracks emerge under Pike Place Market and travel through four at-grade crossings along Alaskan Way on the city's waterfront. The N Line continues northwest past Myrtle Edwards Park and under the Magnolia Bridge to traverse the Balmer Yard, a major BNSF railyard in the Interbay neighborhood.

The tracks cross over the Lake Washington Ship Canal on the Salmon Bay Bridge, a movable bascule bridge near the Ballard Locks, and pass through Golden Gardens Park. The N Line continues north along the shore of Puget Sound and passes under overpasses at Carkeek Park in Seattle and Richmond Beach in Shoreline. The coastline tracks run under steep bluffs to the east that range from 80 to 100 feet (24 to 30 m) in height and are prone to landslides during the winter season. The line enters Snohomish County at Woodway and turns northeast at Edwards Point to reach the Edmonds waterfront. Its first outbound station is Edmonds station, located adjacent to the city's ferry terminal and downtown.