Notice 31st Street Bridge Replacement Over the C&O Canal. The 31st Street Bridge is located in Georgetown and spans the C&O Canal. The bridge is supported on stone masonry abutment walls and an 1867 cast iron multi-column pier. DDOT is replacing the structurally deficient, weight-limited bridge. In the process, the existing historic pier will be removed, restored and reset. In order to perform the work, 31st Street NW will be closed to through vehicular traffic. The bridge will be closed; however, local traffic, deliveries, pedestrian, and bike traffic will be maintained at all time. The detour started the week of June 10th and remain in place until the project is completed in the Summer of 2020. The daily project work starts Monday to Friday at 8.00 am.- 4.00 pm.