When the federal government approved billions of dollars for infrastructure projects as part of the stimulus plan, the intention was to invest in such things as bridges, roads and highways. But officials in Arizona have decided to spend a million dollars of their stimulus funds on … road signs. For the past three decades, signage along Interstate 19 south of Tucson has informed travelers of their destinations in kilometers, not miles. The signs were installed in the early 1980s in anticipation of a changeover to metrics that never came about, so transportation officials figure the time is right to move back to miles.