Set in 2062, “The Jetsons” predicted a future of flying cars and three-day, three-hour workweeks .  In the coming years, we’ll at least get the cars — in the form of small helicopter-plane hybrids that could make commuting a breeze. The flying vessels are just one of several exciting new ways of travel on the horizon. “The future of transit [is] optimistic and ambitious,” Johanna Fabrin — co-founder of 21st Europe, the think tank behind a proposed high-speed rail network linking major cities