Major state highways include SR 94, which connects downtown with I-805, I-15 and East County; SR 163, which connects downtown with the northeast part of the city, intersects I-805 and merges with I-15 at Miramar; SR 52, which connects La Jolla with East County through Santee and SR 125; SR 56, which connects I-5 with I-15 through Carmel Valley and Rancho Peñasquitos; SR 75, which spans San Diego Bay as the San Diego-Coronado Bridge, and also passes through South San Diego as Palm Avenue; and SR 905, which connects I-5 and I-805 to the Otay Mesa Port of Entry. Where does SR 57 flow primarily through?