Nearly three months after its launch, demand for Amtrak's Mardi Gras line is showing no signs of slowing down. Officials say ridership on the train has doubled their initial estimates. | NOLA.com

Amtrak is basking in the afterglow of its new fleet of Acela trains — now racing along one of America’s busiest corridors. But despite being the fastest in the U.S., they still lag behind global high-speed rail. ABC News’ Jay O'Brien reports. | ABC News Live