sound transit is governed by a board of directors with 18 members who are appointed based on their positions in regional and local governments. one seat is held by the washington state secretary of transportation, while the remaining seventeen are allocated proportional to their population within the sound transit district, with each seat representing approximately 145,000 people. the three county executives of king, pierce, and snohomish counties are members of the board and also appoint their remaining seats from local elected positions with approval of the county councils.