About 10 years ago, engineers at the University of Maine’s Advanced Structures and Composites Center developed Bridge-in-a-Backpack, an arch bridge system with components that can be hauled in a bag and quickly assembled to form a span that can reportedly last up to 100 years. But arch bridges represent only a small percentage of the aging bridges that need to be replaced in the U.S., according to Habib Dagher, executive director of the center.
