List of Interstate Highways in Washington
Interstate 90 (I-90) is the longest primary Interstate Highway in Washington, which connects Seattle to Spokane and the Idaho border, measuring , while I-82, connecting the Oregon border city of Umatilla to Elensburg via Yakima, is the shortest at . The longest auxiliary Interstate Highway in Washington is I-405, a bypass of Seattle through the Eastside, at , and the shortest is I-705, a spur into downtown Tacoma, at . One route, I-605, has been proposed over the years to form another Eastside bypass, however there are no plans to construct this fifth auxiliary route.
After passage of the Federal Aid Highway Act of 1956, which formed the Interstate Highway System, the American Association of State Highway Officials had approved I-5 and I-90 across Washington on August 17, 1957. I-82 was approved on October 17, 1957, two months after I-5 and I-90, as part of a addition to the Interstate Highway System.
Blue Ridge Parkway
The Blue Ridge Parkway is a National Parkway and All-American Road in the United States, noted for its scenic beauty. The parkway, which is America's longest linear park, runs for through 29 Virginia and North Carolina counties, linking Shenandoah National Park to Great Smoky Mountains National Park. It runs mostly along the spine of the Blue Ridge, a major mountain chain that is part of the Appalachian Mountains. Its southern terminus is at U.S. 441 on the boundary between Great Smoky Mountains National Park and the Cherokee Indian Reservation in North Carolina, from which it travels north to Shenandoah National Park in Virginia. The roadway continues through Shenandoah as Skyline Drive, a similar scenic road which is managed by a different National Park Service unit. Both Skyline Drive and the Virginia portion of the Blue Ridge Parkway are part of Virginia State Route 48, though this designation is not signed.