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.
List of U.S. Highways in Nebraska
The US Highways in Nebraska are the segments of the national United States Numbered Highway System that are owned and maintained by the U.S. State of Nebraska totaling . The longest of these routes is U.S. Route 30 at around . On a national level, the standards and numbering for the system are handled by the American Association of State Highway and Transportation Officials (AASHTO), while the Nebraska Department of Transportation is responsible for their maintenance. Route numbers are not reused between the various highway systems within the state. For example, Interstate 80 is the only route in Nebraska with the number 80.