Structured Public Involvement in Context-Sensitive Large Bridge Design Using Casewise Visual Evaluation

Subject to engineering constraints, bridges should present a pleasing visual aspect to their user communities. The research team extended its structured public involvement (SPI) protocol using casewise visual evaluation (CAVE) to the field of context-sensitive large-scale bridge design. The context-sensitive design process was used for Section 2 of the Louisville Southern Indiana Ohio River Bridges project. Key design parameters including bridge type, height, symmetry, complexity, and tunnel effect (superstructure shape) were identified by bridge designers. During a 3-month period, an SPI protocol was used to determine community preferences from Kentucky and Indiana participants. Group preferences were gathered rapidly, anonymously, and fairly from a focus group by using electronic polling technology to evaluate potential designs. A preference model was built by using CAVE, and a range of nonlinear preference variations relative to the design parameters was investigated. The favorable public evaluation results of the SPI process using CAVE are presented, and the reasons for its high performance are discussed. Emphasis is placed on the need for a close collaboration between bridge designers and public involvement specialists. The project demonstrates how an analytic approach to public involvement that integrates technology into the dialogic relationship between designers and the public allows for the achievement of inclusive, successful context-sensitive design even for large, complex infrastructure projects.