King County Metro, or Metro for short, is the public transit authority of King County, Washington

King County, Washington

King County is a county located in the U.S. state of Washington. The population in the 2010 census was 1,931,249. King is the most populous county in Washington, and the 14th most populous in the United States....

, a division of the King County Department of Transportation. It began operations on January 1, 1973, but can trace its roots to Seattle Transit, founded in 1939, and Overlake Transit Service, founded in 1927. As of 2008, it operated 1,443 bus

Bus

A bus is a road vehicle designed to carry passengers. Buses can have a capacity as high as 300 passengers. The most common type of bus is the single-decker bus, with larger loads carried by double-decker buses and articulated buses, and smaller loads carried by midibuses and minibuses; coaches are...

es on 223 routes. Its annual ridership in 2008 was 118 million. By first quarter 2009 ridership figures, Metro is the 8th largest agency in the nation.