Just as it is every year, the 2020 Consumer Electronics Show was teeming with prototypes of products once thought to be impossible: flying cars, increasingly sophisticated surveillance tools, even a brand new city of the future. That last idea came from Japan’s largest automaker, Toyota, which recently rebranded itself as a “mobility” company with a focus on developing new technology to change the way people move. The company’s latest plan, announced at CES earlier this month, is to build Woven City—a 175-acre high-tech, sensor-laden metropolis—from the ground up, at the bottom of Mount Fuji in Japan.

The project is expected to break ground in 2021 at the site of a soon-to-be-shuttered car factory, and once completed, Woven City would essentially function as a living laboratory for Toyota’s latest smart technologies. As the company envisions it, buildings, vehicles, and humans will talk to each other through all kinds of sensors, and homes will be equipped with AI assistants that monitor everything from people’s trash to their health. Meanwhile, autonomous vehicles like Toyota’s own E-Palettes—a self-driving shuttle that doubles as a mobile retail store—will move people around as robots underground take care of deliveries. To mitigate the city’s climate impact, buildings will be made of wood, which has a smaller carbon impact than concrete, and the entire ecosystem will be powered through hydrogen fuel.

A lot of these new technologies are already in the works in various Toyota labs across the globe. The idea of Woven City, as Toyota president Akio Toyoda described it during a press conference at CES, is to test all the ideas in one place. It’s not unlike University of Michigan’s mock city, M-City, where the auto industry, including Toyota, has invested millions of dollars for autonomous vehicle research. But the ambition of the newly hyped utopia differs in one key aspect: “We considered creating another testing site for autonomy like M-City,” Toyoda said, “…but we thought, why not build a real city and have real people live in it?”

If Toyota’s ambition sounds familiar, it’s because the company is not the first to propose building a “real,” breathing city—from scratch—that will also a showcase some of their technology of the future. Disney had that same idea when it built EPCOT (Experimental Prototype Community of Tomorrow) in the ’60s, and more recently, tech giants Alphabet Inc. (Google’s parent company), Facebook, and former Microsoft CEO Bill Gates have proposed or begun building their own high-tech communities. Even rapper-turned-entrepreneur Akon has aspirations to build a smart city backed by blockchain technology in Senegal.

Toyota’s plan suggests the appetite is growing for tech developers to experiment in “petri dish” environments, says John Jung, founder of the Intelligent Community Forum, a think tank that focuses on the social and economic development of modern cities. “Toyota and these other companies are looking to take advantage of what technology will be able to do for city building,” Jung says.

The upside is that such environments give innovators a blank slate to fast-track the research and development of big ideas without being stalled by all the regulatory hurdles of an existing city. “It would be a chance to collaborate with other business partners and … scientists and researchers to come work on their own projects [for] however long they please,” Toyoda said.

For its vision, Toyota has enlisted architecture firm Bjarke Ingels to take the lead on developing the masterplan, which aims to let pedestrians, cyclists, and cars coexist with one another. The main element is a grid-like design weaving together three types of streets: one designated for autonomous cars, another for lower-speed little vehicles, and a third—a “linear park,” as the architect Bjarke Ingels described it at the conference—just for pedestrians. The city will also have neighborhoods, parks, and a central plaza that serve as recreational and social gathering spaces for residents. The first 2,000 residents are expected to be employees and their families, visiting scientists, industry partners, retailers, and retired couples.

After that, Toyota is relying on the appeal of a “new way of enjoying life” to get people to move in. “If you build it, they will come,” he said at the press conference, quoting a line from the 1989 film “Field of Dreams.”

In the past, though, that’s been an overly optimistic outlook. Take Songdo in South Korea, one of the earliest “smart cities” built from scratch. Conceived in 2001, developers planned the city around a goal of 300,000 residents. But today Songdo is only a third of the way there, at 100,000 people. And despite lofty promises of a “thriving community,” residents told CityLab last year that they found their city to be cold, lonely, and eerily empty.

In Canada, Alphabet’s Sidewalk Labs continues to face considerable pushback to its proposal for a new experimental neighborhood from Toronto residents worried about transparency and data privacy. Still, Sidewalk Labs has only continued to expand its smart city ambitions in Toronto.

Critics of these projects point out that technology alone does not make a city. If other core elements of urban planning are not integrated into these plans, it’s not surprising that they won’t be positioned for human habitation, says Jung. “If it’s not started from a human-centric perspective, from the bottom up as opposed to from the top down, these aren’t real cities,” says Jung. “They’re not designed to get people to know each other.”

What’s more, Jung and other critics point out that projects focused on showcasing new technology in a vacuum often miss the real, more immediate urban challenges that confront the world’s cities, like pollution, social inequality, and housing insecurity. That Toyota plans to populate its city with people who he says are “signing up” to be part of the experiment also means that the company may not face as much resistance on ethical issues like data privacy.

In his book The Smart Enough City, Harvard researcher Ben Green criticized corporate-run smart cities for having a “narrow vision” that technology is the solution to what cities need to fix. “The persistent desire of technologists to build smart cities from scratch is the strongest indicator that technophiles perceive cities as little more than abstract staging grounds for efficient mobility solutions and service delivery,” he told CityLab in an email.

In his book, Green lays out a vision for the “smart enough city” as an alternative to conceptions like Toyota’s of a “smart city.” “History has told us that the world created under the influence of tech goggles is an undesirable one,” Green writes in his book. “We must instead pursue an alternative vision that bears no imprint of tech goggles. Toyota declined to address questions about these concerns.”

Jung thinks there is still some value in these kind of smart metropolis experiments, as existing cities do want to adopt technology like autonomous vehicles—which automakers are heavily invested in. But they risk being irrelevant “when you design for physical things and you forget the human at the center of it.” After all, he adds, “no city is a utopia.”