The Transit Advisory Board was founded by Seattle City Council Resolution 31572 in March 2015. The Board is composed of 12 regular members - six appointed by the Mayor, five appointed by the Council, and one Get Engaged member. The board advises the Mayor, the City Council, and all departments and offices of the city "on matters related to transit and the possible and actual impact of actions by the City upon all forms of public transportation."

The Board shall:

• Be provided the opportunity to comment and make recommendations on City policies, plans, and projects as they may relate to transit capital improvements, transit mobility, and transit operations throughout the City
• Help facilitate City policies, plans, and projects that support local and region-wide transit mobility efforts, to help ensure a functioning and coordinated transit system throughout the City and region
• Function as the public oversight committee of revenues collected under Seattle Transportation Benefit District (STBD) Proposition 1, which was absorbed into the City of Seattle in June 2016