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.
U.S. Route 59
From the southwestern suburbs of Houston to Downtown Houston, U.S. 59 is commonly referred to as the "Southwest Freeway," sometimes derisively as the "Southwest's Best Freeway." Supporting 371,000 vehicles per day, it is one of the busiest freeways in the United States. U.S. 59 is known as the "Eastex Freeway" in the north/northeast part of the Houston region. At the Mexico–US border, it ends at the World Trade International Bridge in Laredo, Texas. In Laredo, U.S. 59 is co-signed with both Interstate 69W (I-69W) and Loop 20 and has an intersection with Interstate 35 which ends at the Juarez-Lincoln International Bridge. After crossing the bridge into Mexico, Interstate 35 continues as Mexican Federal Highway 85 in Nuevo Laredo which then runs through Mexico and Central America and ends in Panama at the Panama Canal.