The Four Level interchange as seen from above in 1959. Courtesy of the California Historical Society Collection, USC Libraries.
The Four Level interchange as seen from above in 1959. Courtesy of the California Historical Society Collection, USC Libraries.
Fifty-eight years ago today, the Four Level interchange first opened to traffic. This iconic concrete ribbon that binds the 101 and 110 freeways is an almost inescapable feature of many Southern Californians' commute. Admired by some and feared by others, the Four Level was—like many other highway innovations in Los Angeles—the first of its kind and destined to be copied elsewhere.
The Four Level, also known as the Stack, gets its name from its multi-tiered structure that separates traffic heading in each direction into dedicated lanes. On the bottom level are curved ramps for those changing from the 110 freeway to the 101. One level above is the main trunk of the 110 freeway, named the Arroyo Seco Parkway north of the interchange and the Harbor Freeway south of it. On the third level are the arcing flyover ramps carrying traffic from the 101 freeway to the 110. Finally, on the fourth and top level is the main trunk of the 101 freeway, named the Hollywood Freeway to the west and the Santa Ana Freeway to the east.
