In 2016 voters approved Sounder South Capacity Expansion, a comprehensive package of improvements to serve more Sounder South riders at more times of day. The Strategic Development and Implementation Plan is the first step towards achieving that program.

The plan lengthens trains and platforms from seven cars up to 10, serving potentially 40 percent more passengers. Additional projects could include expanded station parking as well as pedestrian and bicycle paths to make it easier for riders to use the system. Sound Transit will also negotiate with Burlington Northern Santa Fe (the railway owns the tracks used by Sounder) to run more daily trips. Once the Strategic Development and Implementation Plan is complete, planning begins for the individual programs included.

Steady growth in ridership

Sounder South runs 13 round-trips between Tacoma and King Street Station in Seattle, eight of which also serve South Tacoma and Lakewood. Sounder also runs special service to select Seahawks, Sounders and Mariners games. Ridership has grown nearly 30 percent since 2014, with each rush hour train carrying more than 875 people on average.