The following articles contain lists of numbered highways in the U.S. state of Washington :
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U.S. Route 99 (US 99) was a main north–south United States Numbered Highway on the West Coast of the United States until 1964, running from Calexico, California, on the US–Mexico border to Blaine, Washington, on the U.S.-Canada border. It was assigned in 1926 and existed until it was replaced for the most part by Interstate 5. Known also as the "Golden State Highway" and "The Main Street of California", US 99 was important throughout much of the 1930s as a route for Dust Bowl immigrant farm workers to traverse the state. Large portions are now California's State Route 99 (SR 99), Oregon Route 99, 99W, 99E and Washington's SR 99. The highway connected to British Columbia Highway 99 at the Canada–US border.
U.S. Route 730 (US 730) is an east–west United States Highway, of which all but 6.08 miles of its 41.78 miles are within the state of Oregon. The highway starts in rural Morrow County in Eastern Oregon at an interchange with Interstate 84 (I-84) and US 30, located east of the city of Boardman. US 730 travels east along the Columbia River as a continuation of Columbia River Highway No. 2 into Umatilla County, intersecting I-82 and US 395 in the city of Umatilla. US 730 and US 395 form a short concurrency within the city before the highways part, with US 730 continuing northeast into Washington. The highway travels through rural Walla Walla County and ends at an intersection with US 12 south of Wallula.
U.S. Route 830, (US 830), was a U.S. Highway which ran between a junction with US 97 near the city of Maryhill, Washington and a junction with US 101 near Ilwaco, Washington. The route still (mostly) exists; however it is currently signed as State Route 14 between Maryhill and Vancouver, Washington, Interstate 5 (I-5) between Vancouver and Longview, State Route 432 for a short stretch through Longview; and State Route 4 from Longview to the western terminus near Ilwaco. The number suggests that US 830 was an auxiliary route of US 30. While US 30 and US 830 never connected, they ran parallel to each other for the entire length of US 830. This route ran on the northern bank of the Columbia River whereas US 30 runs on the river's southern bank, through Oregon.
The 1964 state highway renumbering was a reorganization of state highways in the U.S. state of Washington.
The State Highways of Washington in the U.S. state of Washington comprise a network of over 7,000 miles (11,270 km) of state highways, including all Interstate and U.S. Highways that pass through the state, maintained by the Washington State Department of Transportation (WSDOT). The system spans 8.5% of the state's public road mileage, but carries over half of the traffic. All other public roads in the state are either inside incorporated places or are maintained by the county.
Highways in the United States are split into at least four different types of systems: Interstate Highways, U.S. Highways, state highways, and county highways. Highways are generally organized by a route number or letter. These designations are generally displayed along the route by means of a highway shield. Each system has its own unique shield design that will allow quick identification to which system the route belongs. Below is a list of the different highway shields used throughout the United States.