Four Level Interchange

Aerial photo of the Four Level Interchange; the stack configuration of the interchange is readily apparent (downtown Los Angeles is towards the bottom of this image).

The Four Level Interchange was the first stack interchange in the world. Opened in 1953 at the northern edge of downtown Los Angeles, California, USA, it connects the Harbor, Hollywood, Pasadena, and Santa Ana freeways. The interchange was constructed as a stack interchange because surrounding buildings and terrain made construction of a cloverleaf interchange impractical. Its distinctive architecture has long made it a symbol of Los Angeles' post-World War II development, and it appears on numerous postcards of the 1950s and 1960s. The interchange was once called The Stacks and the 4-H Interchange, mostly by veteran traffic reporter Bill Keene.

Currently, the interchange comprises the following major highways:

• U.S. Route 101 Hollywood Freeway/Santa Ana Freeway
• State Route 110 Pasadena Freeway/Harbor Freeway

Note: Even though the Pasadena Freeway legally ends south of downtown Los Angeles at the Santa Monica Freeway (Interstate 10), "Harbor Freeway" does appear on freeway signs at this interchange.

In July 2006, the freeway interchange has been officially named The Bill Keene Memorial Interchange, in honor of the late KNX and KNXT traffic and weather reporter.