While the classic coastal California road trip follows scenic Highway 1 up the coast of the Sunshine State, the ultimate Pacific Coast Highway (PCH) road trip starts in Seattle on U.S. Route 101 and ends in San Diego. The 101 transitions into Highway 1 near Leggett in Mendocino County, so you never even have to take any exits. Heading south keeps you in the lane closest to the ocean, but, of course, you can head north, too.