Entrepreneur Elon Musk said Thursday a high-speed transportation system that will whisk people between downtown Chicago and O'Hare International Airport at speeds of up to 150 mph could be operational in about three years.

Musk joined Chicago Mayor Rahm Emanuel to formally announce that a Musk-owned enterprise, The Boring Company, was selected for the project and will fully fund it. They say electric vehicles will carry passengers through underground tunnels in about 12 minutes each way.

Emanuel called the new transit system "the fast lane to Chicago's future," and said it will create jobs and make the city more competitive.

He scoffed at critics who question the still-unproven technology or the city's ability to achieve what's been a goal at City Hall for more than a decade. He noted there were doubters when the city set out to reverse the flow of the Chicago River or build the first skyscraper - other seemingly impossible tasks the city now boasts of having accomplished.

"Chicago is always looking at what's possible and then making it achievable," Emanuel said. "There are doubters along the way all the time who sit on the sideline and then when the thing gets built and opportunities come and the job growth happens you can't find them."