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.
New York State Thruway
The New York State Thruway system is a collection of six individual components across the state of New York that connect the state to four neighboring states (Connecticut, Massachusetts, New Jersey, and Pennsylvania) as well as the Canadian province of Ontario. Together, the highways extend for , making the Thruway system one of the largest toll highway systems in the United States. The longest of the six components is the mainline. Of the 570 miles in the Thruway system, (98.4%) carries at least one Interstate Highway designation. Only three sections of the system are not part of the Interstate Highway System; these are the Garden State Parkway Connector in Rockland County, a portion of the Berkshire Connector between its western terminus at exit 21A on the mainline near Selkirk and where it joins up with Interstate 90 at exit B1 near Castleton-on-Hudson, and a short section of the mainline within exit 24 in Albany that is located between where I-87 departs the roadway and I-90 enters it. They are designated as New York State Route 982L (NY 982L), NY 912M, and NY 915H, respectively, all unsigned reference routes. The speed limit, enforced by the New York State Police, is 65 miles per hour along most of the Thruway.