Interstate 90 (I-90), designated as the American Veterans Memorial Highway, is a transcontinental Interstate Highway that runs from Seattle, Washington, to Boston, Massachusetts. It crosses Washington state from west to east, traveling 298 miles (480 km) from Seattle across the Cascade Mountains and into Eastern Washington, reaching the Idaho state line east of Spokane. I-90 intersects several of the state's other major highways, including I-5 in Seattle, I-82 and U.S. Route 97 (US 97) near Ellensburg, and US 395 and US 2 in Spokane.

U.S. Route 2 (US 2) is a component of the United States Numbered Highway System that connects the city of Everett in the U.S. state of Washington to the Upper Peninsula of Michigan, with a separate segment that runs from Rouses Point, New York, to Houlton, Maine. Within Washington, the highway travels on a 326-mile-long (525 km) route that connects the western and eastern regions of the state as a part of the state highway system and the National Highway System. US 2 forms parts of two National Scenic Byways, the Stevens Pass Greenway from Monroe to Cashmere and the Coulee Corridor Scenic Byway near Coulee City, and an All-American Road named the International Selkirk Loop within Newport.