Editing Four Level Interchange (section)

==History==
While the highway oriented east–west at this intersection has consistently been numbered US&nbsp;101, the numerical designation of road oriented north–south at this interchange has changed over the years. Originally designated [[U.S. Route 66 (California)|U.S. Route 66]] and [[U.S. Route 6 (California)|U.S. Route 6]] and later signed as State Route 11, all of these designations were eventually removed from the intersection and replaced with the current designation of Route 110.

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 and opened on 22 September 1953.<ref>{{cite web |url=https://www.laconservancy.org/locations/four-level-interchange |title=Four-Level Interchange |last1= |first1= |last2= |first2= |date=  |publisher=LA Conservancy |access-date=August 2, 2021}}</ref><ref>{{cite web|title=On This Day In Automotive History Motoring|website=365 Days Of Motoring|url=https://365daysofmotoring.com/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-la/}}</ref>

In July 2006, the freeway interchange was officially named in honor of [[Bill Keene]], former [[KNX (AM)|KNX]] and [[KCBS-TV|KNXT]] traffic and weather reporter, although the new name is rarely used. Keene referred to the interchange as "The Stacks" and the "4-H Interchange". During the 1960s, [[Dick Whittinghill]] on [[radio station]] [[KMPC]] sometimes called it the [[four-letter word|Four Letter]] Interchange.<ref>[http://www.floodgap.com/roadgap/110/ Floodgap-Arroyo Seco Parkway]
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The interchange was constructed as a stack interchange because surrounding buildings and terrain made construction of a [[cloverleaf interchange]] impractical. The construction of the interchange displaced over 4,000 people from their homes and cost $5.5 million (${{Format price|{{Inflation|US-GDP|5500000|1952}}}} in {{Inflation-year|US-GDP}}) - making it the most expensive half-mile of highway ever built at the time.<ref>{{cite web |url=http://www.history.com/this-day-in-history/the-famous-four-level-opens-in-los-angeles |title=The famous "four-level" opens in Los Angeles |last1= |first1= |last2= |first2= |date= |website=History.com |publisher=History |access-date=February 21, 2015}}</ref>

The mainline traffic of US 101 is at the top of the interchange, above the ramps, a rarity in stack interchanges. Other examples of similar configurations would later be constructed, including on the [[M25 motorway|M25]] interchange with [[M23 motorway|M23]] passing above the ramps (south of [[London]]), the junction of [[Interstate 695 (Maryland)|I-695]] and [[Interstate 70 in Maryland|I-70]] in [[Baltimore]], and the [[Interstate 805]]–[[Interstate 8]] interchange in [[San Diego]].

Its distinctive architecture has long made it a symbol of Los Angeles' post–[[World War II]] development, and it appears on numerous [[postcard]]s from the 1950s and 1960s.<ref>{{cite web|url=http://www.dot.ca.gov/dist11/photogallery/fourlevel.htm|title=California: District 11: 1954 Four Level Interchange|work=ca.gov}}</ref>