Pacific Coast Highway – SR (State Route) 1 or Highway 101 runs north to south for 655 miles (1055 km) along California’s coast. The section known as the Big Sur runs between St Luis Obispo and Carmel is an official Scenic Highway. It is scenically stunning with plenty of places to pull in and admire the views and access to beaches and parks. It does suffer with landslides that can close the road. The whole route is officially called the Blue Star Memorial Highway to honour American Armed Forces.
San Francisco and it’s historical Golden Gate Bridge are on the route as well as Monterey, Carmel, Long Beach, Los Angeles, St Luis Obispo. The most popular portion and the most scenic is between San Francisco and Los Angeles. As there is no one way rental issue in California and that the cost of a flight is the same into either city it makes a perfect and uncomplicated road trip.
Tip: I would plan an overnight between the major cities perhaps at San Simeon near the Hearst Castle Hearst Castle which is a museum like no other (according the website) the cliff top hotels have viewing places to watch the setting sun over the Pacific. There is a nearby elephant seal colony seal colony that is a popular attraction.