<P> 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 SR 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 inland . </P> <P> SR 1 is part of the California Freeway and Expressway System and is eligible for the State Scenic Highway System . However, only a few stretches between Los Angeles and San Francisco have officially been designated as a scenic highway . The Big Sur section from San Luis Obispo to Carmel is an official National Scenic Byway . </P> <P> The entire route is designated as a Blue Star Memorial Highway to recognize those in the United States armed forces . In Southern California, the California State Legislature has designated the segment between Interstate 5 (I - 5) in Dana Point and US 101 near Oxnard as the Pacific Coast Highway (commonly referred to as "PCH"). Between US 101 at the Las Cruces junction (8 miles south of Buellton) and US 101 in Pismo Beach, and between US 101 in San Luis Obispo and Interstate 280 in San Francisco, the legislature has designated SR 1 as the Cabrillo Highway, after the Portuguese explorer Juan Rodríguez Cabrillo . The legislature has also designated the route as the Shoreline Highway between the Manzanita Junction near Marin City and Leggett . Smaller segments of the highway have been assigned several other names by the state and municipal governments . The legislature has also relinquished state control of segments within Dana Point, Newport Beach, Santa Monica, and Oxnard; those segments are now maintained by those respective municipalities . </P> <P> In addition to connecting the coastal cities and communities along its path, SR 1 provides access to beaches, parks, and other attractions along the coast, making it a popular route for tourists . The route annually helps bring several billion dollars to the state's tourism industry . The route runs right besides the coastline, or close to it, for the most part, and it turns several miles inland to avoid several federally controlled or protected areas such as Vandenberg Air Force Base, Diablo Canyon Power Plant and Point Reyes National Seashore . </P>

Where does the pacific coast highway start and finish