Sixth Street Viaduct

The Sixth Street Viaduct, originally completed in 1932, was one of Los Angeles' most recognizable pieces of infrastructure. Beyond its Art Deco form, it played a critical role in connecting Downtown LA, the Arts District, Boyle Heights, and the LA River corridor, both physically and symbolically.

By the early 2000s, however, the bridge had become structurally unsound. Alkali-silica reaction in the concrete made it seismically unsafe, and engineers determined that retrofitting was no longer viable. The City of Los Angeles faced a rare challenge: replace a beloved landmark while addressing modern requirements for earthquake resilience, multi-modal transport, public space, and long-term durability.

When the city launched an international design competition, the scope went far beyond rebuilding a bridge. The new viaduct was expected to:

• 01 Withstand major seismic events.
• 02 Improve pedestrian and cyclist connectivity.
• 03 Reconnect communities historically divided by infrastructure.
• 04 Activate space beneath and around the bridge.
• 05 Redefine LA's relationship with the river.

Michael Maltzan Architecture, working with HNTB, proposed a design that treated the bridge not just as transportation infrastructure but as civic space, a structure meant to be used, occupied, and experienced at multiple levels. Our role was to help make that proposal clear, believable, and legible at city scale.

At the competition stage, many proposals relied on abstract or symbolic imagery. Here, that approach carried real risk. Decision-makers needed to understand how the bridge would actually sit within the existing city fabric, how its repeated arches would read across long distances, how light, scale, and structure would shape the spaces below, and how pedestrians, cyclists, vehicles, and public life would coexist.

This was not a purely architectural question, it was an urban one. To succeed, the visuals needed to communicate structural credibility, urban integration, and feasibility at full scale, along with a realistic sense of how the bridge would be experienced day to day.

Rather than producing speculative visuals, we treated the project as if it were already moving toward construction, and that decision shaped everything that followed. The bridge was placed accurately within Downtown LA, Boyle Heights, the Arts District, and the river corridor, showing how it reconnects neighborhoods rather than simply crossing them, and how it dissolves the divide between East LA and Downtown.

Aerial views emphasized the viaduct's full length, rhythm, and repeated arches, helping reviewers understand the project as a continuous civic element, not a single object. Concrete, structure, and light were represented as they would behave in reality, reinforcing the proposal's seriousness and technical credibility. And the form had to read clearly from afar, across neighborhoods, freeways, and the river, so the bridge could be understood as a new urban landmark.

The set also looked beneath the structure, revealing the spatial potential of the ground plane: parks, plazas, and community use under the arches.