Residential units under construction near the Lynx Blue Line in CharlottePhoto: Willamor Media via FlickrCharlotte is car-loving NASCAR country, a vast suburbia of cul-de-sacs and strip malls. Yet its new light rail line is a national model for success, outstripping ridership projections and inspiring millions of dollars in high-density development. How did sensible transportation planning come to sprawlburbia? Not by appealing for "sustainability," that's for sure. In the end, the winning pitch that sold voters on light rail was none other than Charlotte's love of growth. The development it lured -- several thousand condos and apartments, dozens of new restaurants …