The cost to repair the nation's aging bridges and roads soared to $2.2 trillion this year, according to a recent American Society of Civil Engineers report. However, some experts say a new wireless sensor technology could alert officials before failures occur and lower the cost of repairs. The sensors, embedded in water-supply systems, bridges and dams, would provide real-time feedback by continuously monitoring parts that keep infrastructure intact. A prototype for use in gas pipes is expected next year. Similar sensors in smart buildings could save billions each year.