Last week, the Uber Elevate conference brought together many bright minds from the aviation industry to help the company convince the world that Uber-dispatched aircraft will soon fly over most major cities.

To help cities wrap their heads around this supposed reality, Uber orchestrated an architecture competition, tapping six winning firms to present their concepts for “Skyports”—the places that Uber’s aerial taxi fleet, named UberAIR, will pick up and drop off passengers.

The skyport concepts had to meet the following requirements: They should be able to serve 4,000 passengers per hour in a three-acre footprint, as well as provide additional places for electric aircraft to charge. Plus, the skyports had to be designed in a way that will have a minimal impact on nearby communities.

As they stand now, these hulking structures are essentially just freeway ramps—limited capacity, car-centric infrastructure that would take up a lot of space in our cities but serve only one purpose—and even getting them to work as well as existing freeways will be challenging.

The first problem I see is with how 4,000 people will be getting to their UberAIR vehicle every hour. To compare, the least-busy stations on Los Angeles’s bustling Red Line subway see about 4,000 boardings per day. Looking at these skyports, I spot a few trains, something that looks like it might be a hyperloop, and some walking paths. But mostly I see dozens and dozens of lanes of freeways and surface streets serving these projects. And many, many cars.

Uber’s CEO Dara Khosrowshahi told The Verge’s Andrew J. Hawkins that UberAIR plans to start testing in 2020 and have a commercially viable service ready by 2023. By then, U.S. cities should be well on their way to achieving their 100 percent renewable energy goals, including ambitious fossil fuel-free street designations, which can really only happen by dramatically reducing the number of cars.

Yet this is clearly car-centric infrastructure, even if it’s all about the air. Because you will be getting to the UberAIR terminal via your Uber car, of course. Even if these Uber vehicles are electric—which they all hopefully will be by 2023—and pooled between two to four passengers, without better ways for people to get there without cars, 4,000 passengers per hour means the facility will have to handle hundreds of vehicles per hour.

The height of these structures is also an issue. Not just the fact that many of them appear to be the tallest building in the neighborhoods they serve, and god bless any architect who believes he might be able to convince a homeowners’ association on LA’s lawsuit-happy Westside to build a small airport on top of a brand-new skyscraper. But the single biggest problem I see with most of these high-rise designs is the challenge of moving 4,000 people up and down elevators every hour.

If you’ve ever visited the Empire State Building in the summer, you know that elevators are not the most efficient ways to move large numbers of people. The fastest, highest-capacity elevators move about 90 passengers at a time.

Will a one-hour commute on a congested freeway be replaced by a one-hour line for the elevator that lifts you to your taxi in the sky?

It’s also notable that, according to the architects, these proposed concepts will move far fewer than Uber’s stated goal of 4,000 passengers per hour—most estimates cap out at a few hundred passengers per hour. So the footprints for these already massive structures would actually need to be much larger for them to be more efficient than existing mass transit options. Which will require bigger buildings and many more elevators—expanding the energy footprint of what will supposedly be a zero-emission transportation network.

The fact that so many of the UberAIR concepts are shown hovering over freeways shows that there is no true innovation in these ideas. Because if all we’re doing is taking low-capacity vehicle freeway traffic, pushing it up into the sky along these same corridors, and creating more bottlenecks as people transfer from one mode to the other, have we really solved an urban mobility problem at all?

Uber’s skyports should be places that provide a myriad of additional benefits for neighborhoods—and don’t create any additional car trips. Even if they’re mixed-use structures, with housing and services, that just happen to have aircraft landing on the roof, there will still need to be many of them located in densely populated neighborhoods to create any kind of usable transportation network. Some existing helipads could possibly be repurposed to accommodate aerial taxis, but the extensive retrofitting of structures can’t justify the cost if these sites can’t meet ridership demands. And then again, elevators.

Perhaps the most palatable idea, from an urban design perspective, is Dallas-based The Beck Group’s low-rise concept that occupies a single city block (below). It’s still towering, monumental, and far from human-scale. But it has the potential to provide some public amenities, like a deep, shaded plaza. And it looks like passengers might be able to access their rides with a single escalator, or even—gasp—by walking up a few flights of stairs.

Right now, Uber is not even totally sure what type of aircraft will be able to achieve the kind of zero-noise, zero-emission standards that will make this service appealing to cities. (The hypothetical vehicles are called eVTOLs for “electric vertical take-off and landing,” and could look more like giant drones.) But most of the aerial taxis currently in development will only be able to seat four people, and the service will still be limited to how many of these vehicles can safely land and takeoff in a skyport’s relatively tiny footprint.

Will a one-hour commute on a congested freeway be replaced by a one-hour line for the elevator that lifts you to your taxi in the sky?

If Uber wants to try to convince cities to welcome their services to their skies—and to be honest, they’re not winning a whole lot of points with city officials at the moment—the company needs to try a lot harder to consider how their airborne ideas fit in to a more sustainable urban mobility future.

In one of a handful of talks at Uber Elevate that focused on the bigger transportation picture, LADOT’s general manager Seleta Reynolds put it bluntly. “The FAA may let you fly,” she said, “but it is the cities that will allow you to land.”