Imagine getting on a train in Denver and traveling south to Albuquerque. Or west to Grand Junction. Bob Briggs thinks it's an idea whose time has come â€“ again. He's a former state representative who's started the Denver-based Rocky Mountain Rail Authority. It's a collection of cities, towns and districts interested in rail options. Briggs proposes two passenger lines. The first would connect Denver and the mountains and run along I-70. A second would follow I-25 from Wyoming to New Mexico. But Randal O'Toole thinks it would be a poor use of tax dollars. He's an economist with the Independence Institute, a free-market think tank in Golden. He says Coloradans won't ride the train. Briggs and O'Toole talk with Dan Meyers.