Plans to build a $1.7 billion commuter train system to Denver International Airport are chugging along, albeit slowly. Planners now need to buy 56 properties for track and rail, and all but five house commercial or industrial businesses, according to The Denver Post . The 24-mile DIA line, part of the Regional Transportation District's FasTracks , would begin at Union Station downtown. Construction on the line is scheduled to begin in 2011. For other lines, RTD needs portions of 44 additional industrial and commercial properties and 14 nonresidential properties. RTD could try to buy the properties, but if it can't broker deals, it could claim the land through eminent domain, paying what officials consider "fair market value." Opinion mongers at newspapers, meanwhile, wonder about FasTracks, which can't afford to provide as much rail as voters were told when they approved a tax hike. TheÂ Rocky Mountain News Â opines that voters may support raising taxes to fill the void. But why not consider money for roads, too? Columnist Dave Perry at theÂ Aurora Sentinel Â wants to know what's taking so long. And please, he writes, don't cut Aurora out of the picture.