As Swire Properties sets out to build one of the boldest developments ever seen in downtown Miami, it hopes to keep one crucial element as low-profile as possible: automobiles.

The Hong Kong developer’s planned Brickell CitiCentre will spend millions of dollars freezing the soil beneath the three-block complex to hold back ground water while it installs a rare underground parking garage in Miami’s downtown. Swire took the unusual step of putting the restaurants for its mall on a top floor in part because that’s the same level as the adjoining station for Miami’s county-run Metromover.

Swire’s top U.S. executive told a business group Wednesday that the $1 billion CitiCentre was designed to thrive in a future where Miami residents are far less enamored with driving to work and play than they are now.

“We don’t think petrol will be $5 a gallon forever,” Stephen Owens, president of Swire Properties Inc., told a breakfast reception held by the Beacon Council, Miami-Dade’s economic-development group. “We’re living in a world of subsidized energy, and we don’t think it can last forever.”

The push to make CitiCentre more pedestrian friendly also meshes with Miami’s ambitions to become more of a 24-hour metropolis, where thriving shopping areas serve both offices and residences. The city’s Miami 21 zoning code now bans developers from building garages at sidewalk level, instead requiring restaurants and shops there to make streets seem more lively for pedestrians. And advocates for Miami’s downtown are pushing for more trees and sidewalk improvements to make the city’s retail offerings more inviting for riders of the city’s under-used MetroMover.

“Everything we do is aimed at making more walkable streets,’’ said Alyce Robertson, executive director of Miami’s Downtown Development Association. For some MetroMover stations, “you get out of the train but you can’t go anywhere.”

As a dense, towering complex on the outskirts of Miami’s current urban core, CitiCentre will depend on an easy flow of customers and residents after its planned opening at the end of 2015. Comprising two residential towers, an office tower anda hotel, and a 520,000-square-foot mall, CitiCentre hopes to become the primary target for downtown Miami’s retail and entertainment dollars. Traffic could be the top challenge for the three-block site off Miami Avenue, roughly one block from the Miami River.

Owens, who lives on Brickell Key, Swire’s last major Miami development, said that eight of the nine regulatory agencies that needed to approve CitiCentre have given the go-ahead to the project. The one hold-out: Florida’s Department of Transportation, which still hasn’t fully agreed to the details of access roads to the property. Owens said he does not expect final approval to be an issue, but traffic is sure to be a primary concern once construction begins in the coming weeks.

Swire’s contractors may ask regulators for permission to fully close South Miami Avenue during parts of the three-year construction phase, Owens said. Closing the street would shorten the disruptions on Miami Avenue, which runs through the CitiCentre site and will require lane closures throughout the building process. Already, one lane is closed to allow access to the new construction site.

Owens said it might be easier on motorists to “bite the bullet and shut it down” in order to get the Miami Avenue work completed sooner.