The Interstate Highways in Washington are segments of the national Interstate Highway System that lie within the U.S. state of Washington. The system comprises 764 miles (1,230 km) on seven routes that are owned and maintained by the Washington State Department of Transportation (WSDOT); the design standards and numbering across the national system are managed by the Federal Highway Administration (FHWA) and the American Association of State Highway and Transportation Officials (AASHTO).