State Route 1 (SR 1) is a major north-south state highway that runs along most of the Pacific coastline of the U.S. state of California. Highway 1 has several portions designated as either Pacific Coast Highway (PCH), Cabrillo Highway, Shoreline Highway, or Coast Highway. Its southern terminus is at Interstate 5 (I-5) near Dana Point in Orange County and its northern terminus is at U.S. Highway 101 (US 101) near Leggett in Mendocino County. Highway 1 also at times runs concurrently with US 101, most notably through a 54-mile (87 km) stretch in Ventura and Santa Barbara Counties, and across the Golden Gate Bridge.
The highway is famous for running along some of the most beautiful coastlines in the USA, leading to its designation as an All-American Road. In addition to providing a scenic route to numerous attractions along the coast, the route also serves as a major thoroughfare in the Greater Los Angeles Area, the San Francisco Bay Area, and several other coastal urban areas.
SR 1 was built piecemeal in various stages, with the first section opening in the Big Sur region in the 1930s. However, portions of the route had several names and numbers over the years as more segments opened. It was not until the 1964 state highway renumbering that the entire route was officially designated as Highway 1. Although SR 1 is a popular route for its scenic beauty, frequent landslides and erosion along the coast have caused several segments to be either closed for lengthy periods for repairs, or re-routed further inland.