Last night at the packed Puente Learning Center, a school in Los Angeles’s Boyle Heights neighborhood, three design and engineering teams attempted to predict the city’s future.

The groups—headed by HNTB, AECOM, and Parsons Brinckerhoff— have all been shortlisted to create the city’s new Sixth Street Viaduct. Their vivid public presentations were the first glimpse of what will likely be LA’s next major icon.

The original 3,500-foot-long structure, a famous rounded Art Deco span designed in 1932, has been deemed unsalvageable due to irreversible decay, and in April the city’s Bureau of Engineering called for a competition to design a new, $400 million, cable stayed structure.

Following the city’s lead, all three teams presented plans that not only showcased memorable forms, but embraced people-friendly designs, including pedestrian paths, parks, and connections to the river below. The push reveals Los Angeles’s focus on attracting people and talent through increased livability. Such moves are a welcome, if uphill battle considering that so much of the city has been designed for cars, not people.

The first presentation, by HNTB with Michael Maltzan Architecture, AC Martin, and Hargreaves Associates, among others, showcased the most exuberant design, a riotous collection of tall and short, slightly canted concrete and cable arches pulsing over the river and well beyond in both directions.

Because of their exact repetition, the concrete spans would be affordable, pointed out the team. They would also be rougher than their steel competition: “The last thing we need is something that looks like it’s meant for a pastoral setting,” explained team member David Martin, a principal at AC Martin.

The arch that spans the river, and a slightly depressed arch below it, would both contain pedestrian walkways which people would be able to enter by literally walking into the bridge.  Below the bridge the scheme would contain a hardscaped Arts Plaza to the west, with restaurants, paths, and graphical representations of the bridge’s boisterous arches on the ground; a slightly softer Viaduct Park, containing a promenade, amphitheater, and skate park; and a landscaped Boyle Heights Gateway to the east, bordering the Boyle Heights neighborhood.

The AECOM plan was centered on a series of three sculptural steel and inverted cable masts, loosely abstracted from images of angels, with a ribbed concrete structure exposed on its underside. The central mast would be the largest, and hence the focal point. A pedestrian path would be suspended underneath while at bridge level lookouts would bulge outward.

The plan calls for several public spaces, including the Mateo Street Gateway Park, a ramping space bordering the Arts district to the west; the Viaduct Plaza, a hardscape under the bridge; the Open Space Paseo under the bridge to the east, and the East Gateway Park, at the entrance to the bridge in Boyle Heights. Steel elements from the original bridge would be used to form lighting for the plazas, existing monuments would be restored, and new pathways to the river would be built around the bridge.

The Parsons Brinckerhoff plan was centered on a smaller mast (the size of the original Sixth Street Viaduct’s collection of piers over the river) that firm principal Ricardo Rabines described as the “wings of LA.” Indeed the steel structure looks like a bird’s wings stretched to fly. Under the bridge a suspended lower walkway would lead to a circular lookout point called the “nest.” Above a colorful covered walkway would split the bridge’s two roadways and, at times, could become a congregation zone, with one roadway shut down for major events. Continuous stairs and elevators would maintain a steady connection to the areas below the bridge.

The proposal included several landscape and planning proposals at the foot of the bridge’s V-shaped columns, some designed by Mia Lehrer, who headed the La River Masterplan, an ongoing effort to make the river a recreational resource. They include an Arts Park to the west containing areas to display art installations; stepping and landscaping of the river below, and a plaza containing a series of clean tech research modules under the bridge to the east.

“It’s important that the bridge engage the river in multiple ways,” pointed out Lehrer.

"You understood what we were looking for," said Mayor Antonion Villaraigosa, who described the city as “people rich and park poor.” “This begins a new era. We’re going to reimagine the city as a place where people can work, play, and recreate.”

The bridge will be paid for substantially by state and federal funds, with just one percent of the money coming from the city, pointed out city councilman Jose Huizar. The winner, chosen by city engineers and the state’s highway building division, will be announced by the end of this year. The design is set to be ready by 2014, with construction completed by 2018. Three more public presentations will take place this week and the next, after which the plans will be presented at the city’s Public Works building on Broadway until October 5.