U.S. Route 101

U.S. Route 101. It is a major north–south U.S. Highway running along the West Coast through the states of California, Oregon, and Washington. Spanning over 1,500 miles from the East Los Angeles Interchange to the Olympic Peninsula, it serves as a vital transportation corridor, scenic tourist route, and historic roadway, famously traversing iconic landscapes like the Big Sur coastline and the Redwood National and State Parks.

Route Description

From its southern terminus at the complex East Los Angeles Interchange with Interstate 5 and Interstate 10, the route heads northwest through the San Fernando Valley and into Ventura County. It famously winds along the spectacular and rugged coastline of Central California, passing through the Santa Barbara area and the dramatic cliffs of Big Sur. In Northern California, it travels through the San Francisco Bay Area, crossing the Golden Gate Bridge into Marin County before entering the famed Redwood National and State Parks. Through Oregon, it closely follows the Pacific Ocean shoreline, serving cities like Brookings, Coos Bay, and Newport. In Washington, it loops around the Olympic Peninsula, providing access to Olympic National Park and terminating near Port Angeles.

History

The highway was originally designated as part of the United States Numbered Highway System in 1926, largely following the path of earlier auto trails like the Pacific Highway and the El Camino Real. Significant early construction challenges were overcome in building the Bixby Creek Bridge and other segments through Big Sur, completed in the 1930s with aid from New Deal programs like the Works Progress Administration. It was a primary route before the construction of Interstate 5, which now handles most through traffic inland. The route has been designated as an All-American Road within the National Scenic Byway program for sections like the Oregon Coast Highway and Redwood Highway.

Major Intersections

Key junctions anchor the route in major population centers. In Southern California, it intersects Interstate 405 in Sherman Oaks and U.S. Route 1 in Oxnard. Through the San Francisco Bay Area, major interchanges include those with Interstate 280 in San Francisco, Interstate 880 in San Jose, and U.S. Route 101's junction with Interstate 5 in Los Angeles is its busiest. In Oregon, it meets U.S. Route 20 in Newport and U.S. Route 26 near Seaside. Its northernmost significant intersection is with U.S. Route 12 in Aberdeen, Washington.

Route Mileage

The total length of the highway is approximately 1,519.71 miles, with the breakdown by state being roughly 796 miles in California, 363 miles in Oregon, and 360 miles in Washington. Mileposts begin at zero at the southern terminus in Los Angeles and increase northward. Notable mileage markers include the start of the Cabrillo Highway designation near LAX, the midpoint in the Redwood National and State Parks region, and the final milepost near Port Angeles. These figures are maintained by state departments of transportation including the California Department of Transportation.

Traffic Volume

Traffic levels vary dramatically from dense urban corridors to remote scenic stretches. The busiest segment is through the San Fernando Valley in Los Angeles, where annual average daily traffic exceeds 200,000 vehicles, as recorded by the California Department of Transportation. Volumes remain high through the Silicon Valley corridor around San Jose. In contrast, sections through Big Sur and the Oregon Coast see significantly lower counts, often below 10,000 vehicles per day, heavily influenced by tourism. Key monitoring points include the Golden Gate Bridge and the Astoria–Megler Bridge into Washington.

Category:U.S. Route 101