Once merely a figment of the imagination, flying cars now are nearly ready for takeoff.

A handful of designs already are undergoing testing, while a number of others are set to take to the air over the next few years. Concerns over technology and high costs could affect the flying car market, yet analysts appear to be optimistic about its success.

“Usually, the best indicator for how far away things are is when you start to see people testing them in real-life situations around the world,” says Jono Anderson, principal-strategy and innovation for consultancy KPMG.

However, observers agree much more development work is needed.

“The biggest challenge is the fact that one has to build the right vehicle, and the ones out there are not right yet,” says Mathias Entenmann, Berlin-based partner at consultant BCG Digital Ventures.

Different concepts have been tried over the years, but current designs are less about cars with wings and more about small vehicles that take off and land vertically, like helicopters but far quieter, for short commutes by air.

“The idea is to unlock the third dimension (vertical) to fly over traffic and reduce commute times,” says Graham Warwick, managing editor of technology at Aviation Week and Space Technology, like WardsAuto, a Penton Media publication. “This requires vertical takeoff and landing (VTOLs) so that air taxis can operate to and from vertiports or vertistops that are close to where commuters live or work.”

Warwick envisions these vertiports in city centers, city perimeters and at major airports that would serve as takeoff and landing spots for flying cars to deliver riders who are willing to pay a premium to dodge traffic in crowded urban centers. Commuters – business travelers are seen as the primary initial audience – would have to use more conventional means to get to a vertiport, meaning the more vertiports there are in a metropolitan area, the more convenient the service. Once there, flying cars quickly could transport passengers to another part of the city for an important business meeting or to the airport for a flight out of town.

U.S. developers account for the lion’s share of activity in the flying-car sector, although companies from France, the U.K., Germany, Japan, Russia, Slovakia and Israel are among those beginning to publicly show concepts.

Within the next five years, at least 10 companies are expected to launch flying cars on the market. Among those are PAL-V, Terrafugia, Aeromobil, Ehang, E-Volo, Urban Aeronautics, Kitty Hawk and Lilium Aviation, all of which have completed at least one test flight of their prototypes.

“Many pieces of the puzzle are coming together at the same time,” Anderson says. “We are able to see them being demonstrated around the world.”

Various developers have adopted different strategies to ensure their designs stand out in the increasingly crowded field, but all are focusing attention around the key issues of safety, noise and efficiency.

“There are programs and regulations under way, but nobody knows how quickly or easily they will be for vehicles (to meet),” Entenmann says.

Meanwhile, developers Aeromobil, PAL-V and Terrafugia already have begun accepting pre-orders for their flying cars.

Dutch manufacturer PAL-V expects to deliver its Liberty flying car by 2018 with costs beginning around $400,000 for its base model. Its Pioneer edition, priced at about $600,000, however, comes equipped with at-home training, power heating and fancy detailing.

The company offers a payment plan to cut the total upfront cost for customers. It is asking for a non-refundable deposit of $25,000 for the top-trim Pioneer, or $10,000 for the base Sport model. But if that is still too much, prospective buyers can place a refundable $2,500 deposit that will put them on a waiting list for now.

As for Aeromobil, pricing will begin at about $1.3 million for its flying car with expected delivery within three years. Aeromobil anticipates its target market to be wealthy supercar buyers, commuters working within a range of 125 miles (200 km) or so from their home, business people tired of wasting time waiting in line for check-in at airports and, most importantly, residents in countries with little or no infrastructure for planes.

Terrafugia’s Transition will be priced at about $279,000, with expected commercial arrival before 2025. The company’s target market includes current pilots and those who desire to become pilots.