The authors have measured an Arnstein gap, that is, a significant difference between desired and actual levels of citizen participation in planning processes. This Arnstein gap exists because even well-intentioned professionals have an unrealistic expectation of achieving consensus across large planning scales. Further, it is often hoped or believed that technologies of representation will somehow accomplish consensus. The authors argue this is not possible without developing a stronger theoretical framework for their deployment in planning in democratic societies. The purpose of this research is to move the public closer to the center of the public infrastructure planning and design process in a productive, efficient, and more satisfactory manner, that is, to close the Arnstein gap. The authors adapt a participatory framework, called structured public involvement (SPI), for integrating visualization and geospatial technologies into large-scale public involvement in planning domains. The authors discuss how SPI using the casewise visual evaluation method is applied in collaboration with planners. A case study is presented of integrated transportation and land-use planning for an Indiana city. The results demonstrate that SPI achieves high levels of stakeholder satisfaction in addition to providing high-quality planning and design guidance for professionals.