This study, prepared for the Transportation Research Board’s National Cooperative Highway Research Program, focuses on isolated nonattainment and maintenance rural areas, which are rural areas not located within a metropolitan nonattainment or maintenance area.  Isolated rural areas face different transportation conformity process requirements under the Clean Air Act than metropolitan areas, and typically have limited access to resources and technical tools.  This report provides practical information to help transportation staff better understand the conformity requirements in isolated rural areas and the actions that need to be taken to meet them. Click here to view the report.