Tuesday 22nd September 1953

The first four-level (or ‘stack’) interchange in the world opened in Los Angeles, California, at the intersection of the Harbor, Hollywood, Pasadena and Santa Ana freeways, where 32 lanes of traffic weaved in eight directions at once. The four-level reinforced concrete structure was designed by a team of engineers and built by the James I. Barnes Construction Company. Although it was finished in 1949, it was not put into full use until the freeways it served were completed four years later. The interchange, sometimes called “The Stack,” was retrofitted after the 1994 Northridge earthquake and renamed the Bill Keene Memorial Interchange after the late local traffic and weather announcer in 2006. It is the only interchange in the region to be certified as a civil engineering landmark by the Society of Civil Engineers, and its robust elegance is a true aesthetic achievement. As the Los Angeles Times said in 1949, “It’s the most photogenic pile of cement in town.”