FasTracks is nearly $1.5 billion over its original $4.7 billion budget, forcing RTD to look even more closely at hiring private companies to build and operate rail lines. The new, $6.2 billion total - a 32 percent increase - reflects requests for extras on FasTracks corridors and unexpected spikes in things such as steel, concrete and copper. "The cost increases in construction materials really whacked us," Cal Marsella, RTD general manager... One example: the cost of steel to be used in tracks, bridges and other structures went up from an average of 73 cents a pound in Colorado in 2003,...