History of Interstates and U.S. Highways in Washington

Washington’s highways have been essential for connecting its major cities, ports, and natural landscapes. Early routes such as U.S. 101 and U.S. 2 provided crucial links for the movement of goods and people. With the development of the Interstate Highway System, major Interstates like I-5, I-90, and I-82 became vital for long-distance travel and commerce across the Pacific Northwest.

Washington’s highways play a critical role in supporting the state’s economy, particularly in sectors such as trade, technology, and agriculture. I-5, which runs from the Canadian border to Oregon, is one of the busiest highways on the West Coast. I-90, the northernmost transcontinental interstate, connects Seattle to cities in the Midwest and East Coast, while I-82 links the state’s central agricultural region with major urban centers.

Washington is continuously investing in its highway infrastructure, with recent projects aimed at improving traffic flow, reducing congestion, and modernizing aging infrastructure. Ongoing efforts include expanding capacity on I-5 and I-90, as well as constructing new routes like the SR 520 floating bridge to handle growing traffic demands in the Seattle metropolitan area.

Why all the 1926 dates? The year 1926 was significant for the U.S. highway system because it marked the official establishment of the U.S. Numbered Highway System, also known as the U.S. Highway System. This system was created by the American Association of State Highway Officials (AASHO), now known as the American Association of State Highway and Transportation Officials (AASHTO), in cooperation with the federal government. Here’s why 1926 was pivotal:

1 Standardization of Routes: Prior to 1926, roads in the United States were a patchwork of local and state routes, often inconsistently marked and poorly maintained. The U.S. Highway System brought about a standardized network of numbered routes, designed to provide uniformity across state lines, making travel more predictable and navigable for drivers.

2 National Connectivity: The new system connected rural and urban areas across the country, linking small towns and cities with major economic hubs. This was essential for improving the transportation of goods and services, helping to bolster the national economy.

3 Designation of Major Routes: Iconic highways such as U.S. 1 (from Maine to Florida) and U.S. 66 (from Chicago to Los Angeles, later known as "Route 66") were part of this network. These routes became crucial arteries for cross-country travel, commerce, and later, American culture.

4 Foundation for the Interstate System: The 1926 U.S. Highway System laid the groundwork for the more advanced Interstate Highway System, which was developed decades later in the 1950s under President Eisenhower. Many U.S. Highways continue to serve alongside interstates, and some of the old U.S. highways are still in use today.

The year 1926 thus represents the beginning of a modern, structured approach to road travel in the United States, which revolutionized transportation and mobility across the country.

Busiest and Longest Federal Interstates and U.S. Highways in Washington