It is a bypass auxiliary route of I-5, running roughly through the center of the Greater San Diego region from San Ysidro (part of the city of San Diego) near the Mexico–U.S. border to near Del Mar. The southern terminus of I-805 at I-5 in San Ysidro is less than a mile north of the Mexican border.
Merupakan bypass dari I-5, melalui pusat Wilayah Greater San Diego dari San Ysidro (bagian dari kota San Diego) dekat Perbatasan Meksiko–AS sampai dekat Del Mar. Ujung selatan I-805 pada I-5 di San Ysidro berjarak kurang dari satu mil di sebelah utara perbatasan dengan Meksiko.