The I-405 Mulholland Drive Bridge Comes Down in Pieces
In 1962, my father and I drove thirty-miles from Burbank to Santa Monica, California. New that year and new to us was a 4.1-mile stretch of Interstate I-405. In true California fashion, the new freeway went straight up and over Sepulveda Pass. Its predecessor, Old Sepulveda Blvd. wound its way up and over a longer, more arduous route.
The new freeway featured four lanes in each direction, so traffic flowed with ease. A chain-link safety fence separated the northbound and southbound lanes. My father’s car was a 1962 Impala SS, with a 327 V-8 engine and a four-barrel carburetor. Gasoline was less than fifty cents per gallon and the speed limit was sixty-five miles per hour, which we easily reached.
At the top of the pass, the roadway curved gently to the right and then traveled under a marvel of a concrete bridge, spanning the freeway without any center support. Unlike any previous span in the Los Angeles area, the new Mulholland Drive Bridge was tall, graceful and elegant in its proportions. Despite its size and novel construction methods, the price tag for the bridge was only $1.8 million.
By 1964, my friends and I used “the i405” as our quick conduit to the beach in Santa Monica. On a good day, we could travel the thirty miles in less than an hour. Even though the freeway was less than three years old, parts of the concrete roadbed had started to shift and sag. This made the downhill run from the top of Sepulveda Pass to Sunset Blvd. a white-knuckle ride in my friend Bill’s 1957 Chevy Belair. As the road heaved and turned, we passengers held our breath at the approach to each turn. Although the classic Chevy looked cool, handling on a rough and curvy road was not its forte. As Bill clutched the wheel, The Rolling Stones', “Satisfaction” blared out of the car radio.
In 1962, California's population was seventeen million. According to the 2010 census, the population of California is more than twice that, now standing above thirty-seven million. Repaved and widened several times, the I-405 through Sepulveda Pass simply cannot handle twice as many cars as its designers intended. What is the latest solution? Widen it again, of course.
In order to squeeze a carpool lane into the northbound direction, the elegant and timeless Mulholland Drive Bridge will come down in halves, beginning mid-July 2011. If all goes as planned, our former “bridge to the future” will disappear by half over a three-day weekend. During the planned 53-hour closure, the southern half will come down in a cloud of construction dust and debris. Despite adequate warning to stay away from the planned freeway closure, you can bet that many in Los Angeles will not get the message. Oblivious or curious, they will head for the beach or the Valley that weekend. After all, freeway traffic jams, called sig-alerts in LA, are a time-honored tradition.
On that day in 1962, my father looked up at the bridge as we approached and asked, “Do you know how they built that?” In my awe of the whole scene, I said, “I have no idea. How did they do it?” “I read about it in California Highways," he said. "It's a free magazine, telling us all about our new freeways and how they build them. According to the magazine", he said, “they dug six holes almost one hundred feet deep into the mountain. Then they built the six support columns in those deep holes. Next, they built the bridge deck, which hovered just above old ground level. Although the support columns are solid, reinforced concrete, much of the horizontal structure is hollow. Rather than spanning that wide gulf with steel girders, the bridge relies on prestressed, reinforced concrete tubes to carry the load. After every aspect of the bridge was completed, workers with heavy equipment dug out all the earth beneath the bridge, slowly revealing its final height. It is towering above right now", he said as we passed beneath the shadow of the bridge.
Last winter I shot a few pictures of the Mulholland Drive Bridge, while traveling northbound in the afternoon rain. This week, I traveled in each direction over Sepulveda Pass and shot a few more images for posterity. After mid-July 2011, one half of this iconic bridge will be missing from the Los Angeles skyline. Until its two-phase bridge replacement reappears in several years, the I-405 through Sepulveda Pass will remain a work in progress, much as it has for the past fifty years.
In 1966, loss of a Rose Bowl berth to USC precipitated the "UCLA Rampage", which led to the first closing of the San Diego Freeway (I-405 Northbound).
Email James McGillis