Abstract: An improved box beam bridge and a method of construction are disclosed. The box beam bridge comprises a plurality of box beams for each lane structure of the bridge. Each of these lane structures are separately secured together and post-tensioned by means of a composite material strand. The separate lane structures are then brought together to complete the bridge width, with an interstitial box beam placed between the separate lane structures. Once arranged together, the separate lane structures and integrated interstitial box beam are secured together and post-tensioned by a second composite material strand that runs the entire width of the bridge.