Whittier Boulevard is an arterial street that runs from the Los Angeles River to Brea, California. The street is one of the main thoroughfares in both Whittier and East Los Angeles. At various times, portions of Whittier Boulevard carried the designation of U.S. Route 101. Whittier Boulevard also carries a portion of El Camino Real. Its west section leading from the Sixth Street Viaduct was demolished in 2016; the replacement was officially opened in 2022.. Currently, Whittier Boulevard carries two Caltrans controlled highways. The portion between Rosemead Boulevard and Beach Boulevard carries State Route 72 and the portion between Beach and Harbor Boulevards carries California State Route 39. The portion of State Route 72 up to State Route 19 was relinquished back to Pico Rivera in the early 2000s and the portion of State Route 72 between State Route 19 and Downey Road was deleted from SR 72 in 1992.

El Camino Real is a 600-mile (965-kilometer) commemorative route connecting the 21 Spanish missions in California, along with a number of sub-missions, four presidios, and three pueblos. Historically associated with the Calle Real which terminates in Mexico City, as the former capital of New Spain and the seat of royal power for Las Californias, its southern end in the modern U.S. state of California is at Mission San Diego de Alcalá and its northern terminus is at Mission San Francisco Solano.