Secondary and Cumulative Effects of Replacing the Woodrow Wilson Bridge: Process and Conclusions

Abstract

Analyzing the secondary and cumulative effects of transportation projects requires objectivity, flexibility, creativity, and close coordination and cooperation between the project team, review agencies, and private organizations that provide information. Although guidelines and processes are available that supply possible approaches, the unique circumstances of each project necessitate a secondary and cumulative effects analysis (SCEA) methodology that assesses the specific resources potentially affected and represents a consensus of the team and reviewers. “Secondary effects” can be defined as effects that are caused by the action and are later in time or farther removed in distance, but are still reasonably foreseeable. “Cumulative effects” are environmental effects that result from the incremental effect of the action when added to other past, present, and reasonably foreseeable future actions, no matter what agency (federal or nonfederal) or person undertakes those other actions. The SCEA for the Woodrow Wilson Bridge Project was uniquely challenging for the multiagency client (FHWA, Maryland State Highway Administration, Virginia Department of Transportation, and the District of Columbia Department of Public Works) and the resource and review agencies who had to agree on a process and methodology. The success of the process was a result of the close and constant collaboration among the project team, the client, and the resource agencies. A description of the process and illustration of the methodology are provided along with a sampling of different environmental resource components. Also covered are lessons learned that could be applied to other transportation projects.