Autonomous flying cars have always seemed like a futuristic innovation that belongs more on the silver screen than in real life, but Boeing is making rapid headway on the concept and its top executive says we could see the first operational self-driving airborne vehicles take to the skies in under five years. Speaking at the GeekWire Summit, Boeing CEO Dennis Muilenburg laid out the company's vision for flying cars, as well as the importance of safety measures for the concept. Muilenburg said the company is already building prototypes and expects them to fly within the year. "Imagine a future city that has three-dimensional highways, with flying taxis, flying cars," Muilenburg said. "That future is not that far away.