Speaking on Tuesday at an investor forum in Tokyo, Uber CEO Dara Khosrowshahi predicted that his company’s Uber Air flying taxis will be commercialized and used widely within the next five to ten years. According to Reuters, which earlier reported on the event, Khosrowshahi said that he believes the flying taxis, which instead of riding on roads will carry passengers around an area at low altitudes, will actually become affordable means of travel for consumers.

Uber has been working on the flying taxi concept for well over a year, but started to reveal more details on its plans in 2017. In addition to working on the vehicles that will carry passengers, Uber in November announced that it had partnered with NASA to develop an air traffic management system that will keep those passengers safe.

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Uber has previously said that it would like to launch its first flying taxi service in Dallas, Dubai, and Los Angeles in 2020. Those test markets will inform the company’s plans and allow it to make tweaks before it launches Uber Air in more places in the coming years.

Khosrowshahi didn’t say in the interview which cities would get Uber Air after that initial test period is completed.