Public investment in transit and streetscape improvements can encourage private development, and subsequently increase transit ridership and reduce pollution. Portland, OR’s Metro regional government has developed investment scenarios designed to reduce light vehicle carbon emissions. Adopting a regional scenario requires public review and consultation with local governments who will implement the comprehensive plans and land-use regulations. Decision makers and residents need to understand potential benefits: ways in which targeted investment could generate more livable urban spaces while reducing greenhouse gases. Illustrations can show how the investments could shape the pedestrian experience through trees, street furniture, buildings, open spaces, etc. This report explains a new workflow to illustrate urban development possibilities that can be adjusted according to evolving forecasts. Developing accessible scenario illustrations from city and regional planning forecasts requires sound analysis and thoughtful graphics to effectively communicate the analysis results. Our workflow connects planning forecasts (incorporating economic, transportation and land development data) to a parametric urban modeler to generate development massing, with views refined with 3D and 2D graphic procedures. Our objective has been to streamline the creation of visuals that communicate community development patterns and amenities provided with different levels of investment. A streamlined procedure allows different designers to generate illustrations with a consistent graphic style. The report documents the workflow, and identifies challenges, opportunities and questions for further work.