Case Study: Sixth Street Viaduct — Competition Architectural Visualization

International Design Competition | Public Infrastructure | Los Angeles

Client: Michael Maltzan Architecture (in collaboration with HNTB)
Location: Los Angeles, California
Project Type: International Design Competition
Scope: Photorealistic Architectural Visualization
Primary Focus: Aerial & Contextual Views

Context

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:

Withstand major seismic events
Improve pedestrian and cyclist connectivity
Reconnect communities historically divided by infrastructure
Activate space beneath and around the bridge
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.

The Challenge

At the competition stage, many proposals relied on abstract or symbolic imagery. In this case, 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
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
Feasibility at full scale
A realistic sense of how the bridge would be experienced day to day

The imagery had to feel real, not conceptual.

Our Approach

Rather than producing speculative visuals, we treated the project as if it were already moving toward construction. This decision shaped everything that followed.

Key priorities included:

Urban Integration – The bridge was accurately placed within Downtown LA, Boyle Heights, the Arts District, and the river corridor—showing how it reconnects neighborhoods rather than simply crossing them.

City-Scale Legibility – 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.

Material and Structural Realism – Concrete, structure, and light were represented as they would behave in reality, reinforcing the proposal’s seriousness and technical credibility.

Clarity at Distance – The form needed to read clearly from afar—across neighborhoods, freeways, and the river—so the bridge could be understood as a new urban landmark.

The Role of Visualization

The visuals became a critical part of the competition narrative:

Demonstrating how the bridge dissolves the divide between East LA and Downtown
Revealing the spatial potential beneath the viaduct — parks, plazas, and community use
Communicating the project’s multimodal ambition: vehicles, bicycles, pedestrians, and public life coexisting

Rather than selling an idea, the imagery presented a future reality.

Outcome

The proposal by Michael Maltzan Architecture and HNTB was selected as the winning entry of the international competition.

Years later, the new Sixth Street Viaduct was completed and opened to the public—now widely recognized as one of Los Angeles’ most significant contemporary infrastructure projects. It delivers:

One of the most earthquake-resilient bridges ever built in the region
Expanded pedestrian and cycling access
Activated public space beneath the structure
A new civic landmark for the city

The built result closely reflects the vision communicated during the competition phase.

Why This Project Still Matters

This project reinforces a principle that continues to guide our work:

When visualization is used to reduce uncertainty rather than embellish ideas, it becomes a powerful decision-making tool.

For competitions, approvals, and large-scale public projects, clarity builds trust. Trust enables approval. And approval allows ambitious projects to move forward.

The Sixth Street Viaduct remains a strong example of how accurate, context-driven visualization can help translate complex urban ideas into outcomes that cities are willing to build.