High Quality Content by WIKIPEDIA articles! The Washington State Department of Transportation (WSDOT), was established in 1905. The agency, led by a Secretary and overseen by the Governor, is a Washington governmental agency that constructs, maintains, and regulates the use of the state's transportation infrastructure. WSDOT is responsible for more than 20,000 lane-miles of roadway, nearly 3,000 vehicular bridges and 524 other structures. This infrastructure includes rail lines, state highways, state ferries (considered part of the highway system) and state airports.