Constructed in 1932, the Sixth Street Viaduct (also known as the Sixth Street Bridge) is an important engineering landmark in the City of Los Angeles. It is one of a set of fourteen historic Los Angeles River crossing structures, and is the longest of these structures.
Located in a highly urbanized area just east of downtown Los Angeles, the bridge is a critical transportation link between LA Arts District and Boyle Heights. A 1986 Caltrans bridge survey found it to be eligible for inclusion in the National Register of Historic Places.
The Sixth Street Viaduct (designated as City of Los Angeles [City] Bridge No. 53C-1880 and California Department of Transportation [Caltrans] Bridge No. 53-0595 [portion of viaduct over Hollywood Freeway or US 101]) has an overall length of 3,500 ft., and extends east-west across the Los Angeles River, multiple railroad tracks, US 101, and several local streets. It has a 46 foot wide, four-lane roadway with 11-foot eastbound and westbound inside traffic lanes and 12-foot outside lanes with no shoulders. There are sidewalks of varying widths on both sides.
The Sixth Street Viaduct was constructed using then state-of-the-art concrete technology and an onsite mixing plant. However, just 20 years after the Sixth Street Viaduct was constructed the cement supports began to disintegrate due to a chemical reaction known as Alkai Silica Reaction (ASR), causing significant deterioration of the structure.
Over the years, various costly restorative methods have been tried, but none have worked to correct the problem. The results of seismic vulnerability studies, completed in 2004, concluded that the viaduct, in its current state of material deterioration and lack of structural strength, has a high vulnerability to failure as a result of a major earthquake. In addition to its vulnerability to collapse under predictable seismic forces, the Sixth Street Viaduct also has geometric design and safety deficiencies.
The Replacement Viaduct
As a result of its declining condition, the Sixth Street Bridge is in need of replacement. The City of Los Angeles, Bureau of Engineering is working in partnership with the California Department of Transportation (Caltrans) to design a new bridge.
The new bridge will incorporate the following features and benefits:
- Creates Roadway Shoulders
- Provides Wider Sidewalks
- Removes Kink in Bridge
- Provides Safety Median Buffer
- Multimodal: Pedestrians & Bikes
- River Access & Enhancements
In September 2012, the City of Los Angeles undertook a Design Competition to select a design for the new viaduct. For more information on the design competition firms and designs click here. In December 2012, the Bureau of Engineers alongside Mayor Antonio Villariagosa and Councilmember Jose Huizar, 14th District announced the winning firm, HNTB. See the winning design presentation boards here. In July 2013, the City recommended the joint venture of Skanska/Stacy and Witbeck to construct the new $400 million Sixth Street Viaduct Replacement Project and in December 2013 their contract was approved.
Currently there are public briefings regarding updates and key matters in the design and development of the new viaduct. A full archive of past meetings including the agendas and presentations can be viewed here. For upcoming meetings or to see a proposed calendar of the full project please click here.
See the most recent Public Briefing Information and Videos below:
December 5, 2013
Agenda for December 2013 Public Briefing (Bilingual) (4.8 MB, PDF)
Flyer for December 5, 2013 Public Briefing - English (929 KB, JPG)
Flyer for December 5, 2013 Public Briefing - Spanish (897 KB, JPG)
View a VIDEO of the Public Briefing on 12/5/13 below:
View the powerpoint presentation from the 12/5/13 Public Briefing in video format below:
AREA MAP of the Sixth Street Viaduct Surrounding Community
(See below or click HERE for an interactive map)