(For the never-built spur in Portland, Oregon, see Interstate 505 (Oregon).) Interstate 505 (I-505) is an Interstate Highway in California between Interstate 80 in Vacaville and Interstate 5 near Dunnigan. I-505 is primarily a rural interstate, but travels through Vacaville and the city of Winters. The interstate is the primary route connecting the San Francisco Bay Area and the northern Sacramento Valley, bypassing Sacramento and its attendant city traffic. Thus, it is a major route for travelers heading directly from the San Francisco Bay Area to the Pacific Northwest.