Courtesy National Park Service This tunnel under the bridge is aimed at improving pedestrian and biker safety, according to the National Park Service. Courtesy National Park Service A map of improvement projects the National Park Service will be working on over the next year. Courtesy National Park Service (1/3) The National Park Service on Wednesday announced a list of changes they’ll implement over the next year that will better connect areas on the National Mall and improve safety for pedestrians and bikers. The work will include the rehabilitation of trails and roads to create new and enhanced infrastructure for visitors to the Mall. There will be closures and detours while the process is ongoing.