People have been wishing for flying cars since the earliest days of flight and automobiles. Does Tesla’s demonstration earlier this month of a “flying” version of its new Roadster mean we’re close?

If you’re looking for a car that can safely travel on roads and highways while also flying significant distances, then no. But if you want a personal flying machine that operates at relatively low altitudes and travels the distance of most car trips, that’s closer to reality.

Enter the fast-growing world of electric vertical take-off and landing aircraft, known by the somewhat cumbersome acronym of eVTOLs. They can’t travel on highways, and some don’t even have wheels. But many companies have been racing to develop vehicles straight out of science fiction movies and cartoons, with a few already selling aircraft.

“The idea of the ‘flying car’ has captured the public imagination for generations, and today that excitement is driving real investment and innovation across the industry,” said Kristina Menton, vice president of flight at Pivotal, one of the companies making eVTOLs. “The appeal is easy to understand. Why spend 90 minutes in traffic when you could spend 20 minutes in the sky?”The eVTOLs are very lightweight compared to traditional cars, with limited carrying capacity, and can generally fly 100 miles at a time at most.

They also can’t operate on roads.

But even without driving over asphalt, some proponents believe eVTOLs should be considered an automobile in the strictest definition of that word – a vehicle that can transport you from point A to point B. Flying “cars” can appeal to drivers who want to avoid “roads (that are) are problematic and congested,” said Rani Plaut, cofounder and CEO of Air, an Israeli company that plans to build eVTOLs at a facility in Florida.

One company that claims to be developing a true flying car is California start-up Alef. CEO Jim Dukhovny said the initial version, which will have a top speed of about 55 mph, was designed to be both an aircraft and a car instead of adapting one or the other.

The 254-pound vehicle uses eight propellers inside its body to get airborne but also has four wheels and is designed for driving. The “Model A” can only carry one person that weighs less than the empty vehicle and doesn’t have standard safety equipment like airbags.

But Dukhovny wants it to be thought of as a car, not an eVTOL.

“EVTOLS are for the aviation market,” he said, “Our competition is Toyota, Ford, Tesla.”But trying to do both, operate as a car and an aircraft, faces many basic engineering problems, said Roger Connor, curator of the vertical flight collection at the Smithsonian’s National Air and Space Museum. That’s because aircraft are sensitive to weight, while cars need heavy equipment.

“Something that is a hybrid between the two is going to be a poor-performing aircraft and a poor-performing vehicle,” he told CNN.

Still, the Federal Aviation Administration has pushed for the development of eVTOLs, launching a series of testing programs across 26 states in March.

The future of aviation is here — and it’s going to dramatically improve how people and products move,” said Transportation Secretary Sean Duffy when announcing the program.

One thing the FAA is investigating is who will be allowed to fly these aircraft. The expectation is that it will take far less training to fly an eVTOL than to pilot a small plane, helicopter or passenger plane – perhaps as short as a few days. But that is still a work in progress, Connor said.

“We haven’t licensed anybody in these new category aircraft yet,” he told CNN. “This is little bit of a new thing for everybody, and it is especially so for the FAA, since the aircraft are not airplanes and they’re not helicopters.”Despite an appetite from the FAA, eVTOLs are still very much in development. Very few have been built and delivered to customers, and those available are very expensive.

Larger versions, or “air taxis” that carry a handful of passengers, will cost more than $1 million each, Connor said. Those for personal use will retail for less, but still cost anywhere from $60,000 up to $400,000 for a two-seat aircraft with some endurance and range.

“For $60,000, you’re basically getting a fancy drone that could carry 160 pounds or so for maybe 10 minutes,” he added.

Tesla has yet to say how much a “flying” version of its Roadster will cost, and no version, flying or grounded, will be for sale until at least 2028.

Unlike most eVTOLs, which use propellers, the Roadster utilized compressed air jets to leap over other cars and propel from the top of a ramp six or seven stories high during its product reveal earlier this month.

The Roadster also did not fly any appreciable distance, landing short of even the 120 feet the Wright Brothers achieved during their first flight at Kitty Hawk, North Carolina, in 1903. Tesla’s own site cautions the test model is “not approved for public road use.”Still, the splashy demonstration has many in the industry cheering.

“When a company with Tesla’s reach puts the idea of everyday people leaving the ground in front of millions of viewers, it widens the conversation, and the industry benefits from that curiosity,” said Pivotal’s Menton. But she cautions that her company is not a car company. “We build aircraft, not flying cars,” she said.