These are boom times for passenger rail transit in Los Angeles. There are already more than 80 miles of light rail and subway lines in the L.A. area and lots more are either under construction or planned, from Santa Monica to Azusa. It’s not just about getting passengers from place to place. City boosters hope that rail stations and lines will be a powerful magnet for investment and economic development in neighborhoods that need both. Some are already saying that where the trains go, gentrification soon follows. But is that really true? KCRW's Saul Gonzalez has our feature story.