The bridges, built roughly sixty years ago, had reached the end of their service lives and were suffering from deterioration. The concrete of the bridge decks was in poor condition. The steel beams under the concrete decks were also in need of repair. MassDOT replaced the steel beams and concrete decks, which together make up the part of the bridge called the superstructure. The bridges’ piers and abutments, which make up the bridges’ substructures, were in good condition. MassDOT repaired the fourteen bridge substructures and revised them to fit the replacement superstructures.