San Fernando Road starts at its intersection with Sierra Highway in the Sylmar neighborhood of Los Angeles.

The Old Road runs parallel to Interstate 5 and serves the Stevenson Ranch, Valencia, and Castaic neighborhoods in the western Santa Clarita Valley.

[1] The portion between Sun Valley and the city of Burbank is mostly industrial, with heavy truck traffic through this area.

At the intersection with Lincoln Street, there is an interruption in the route due to the reconstruction of the interchange with Interstate 5, with no direct link to the portion of San Fernando Boulevard that runs east of the freeway.

Today, San Fernando Road is used as an alternative to Interstate 5 between Lincoln Heights and the Newhall Pass, due to the relatively few traffic signals on the route.

The former Southern Pacific Railroad, which now carries the Antelope Valley Line of the Metrolink rail system, follows both portions of San Fernando Road for their entire routes.