Tilly Chang serves as Executive Director of the San Francisco County Transportation Authority. The Transportation Authority's mission is to make travel safer, healthier, and easier for all. The agency plans, funds, and delivers transportation projects to improve travel choices for residents, commuters, and visitors throughout San Francisco.  
 
Ms. Chang oversees the Transportation Authority's administration of San Francisco’s half-cent transportation sales tax and other voter-approved funding programs. She also leads the agency's congestion management functions, including developing the San Francisco Transportation Plan, which is the blueprint for citywide transportation policy and investment.  
 
Ms. Chang is Chair of the Self-Help Counties Coalition and serves as Vice-Chair of the Transbay Joint Powers Authority's Peninsula Rail Program Executive Steering Committee. She serves on the boards of the Intelligent Transportation Society of America, UC CONNECT Advisory Committee, and Self-Help for the Elderly.

Prior to the Transportation Authority, she held posts with the World Bank, Metropolitan Transportation Commission, and a wireless technology startup. She is a graduate of UC Berkeley and M.I.T.