SR 1 then becomes a freeway once again at Sharp Park in Pacifica before turning inland to join Interstate 280 in Daly City. Just short of reaching the City and County of San Francisco, SR 1 splits from Interstate 280, where the road becomes Junipero Serra Boulevard. Shortly thereafter, the highway makes a slight left, becoming the six-lane wide 19th Avenue; the San Francisco Municipal Railway's M Ocean View streetcar line runs in the median from this point until a junction to a rail only right-of-way near Rossmoor Drive. SR 1 then turns into Park Presidio Boulevard after it passes through the city's Golden Gate Park. Then after entering the Presidio of San Francisco, it goes through the MacArthur Tunnel before joining US 101 for a fourth time on the approach to the Golden Gate Bridge known as Doyle Drive.