Today's bridges are remarkable feats of engineering. But many are getting near the end of their useful lives. Cleveland's Innerbelt bridge is one of those. The span, opened in 1959, is about to get a major makeover, perhaps with an infusion of federal stimulus money. The question for the Innerbelt bridge and others like it around the country is how to design bridges that are strong, safe, and last for generations? And what to do when they don't . Some answers Monday at 9:00 a.m. on the Science Café edition of The Sound of Ideas.