Quantifiable Application of Performance-Based Design

Abstract

The 7th edition of the American Association of State Highway Transportation Officials (AASHTO) document, A Policy on Geometric Design of Highways and Streets, also referred to as the Green Book, defines performance-based design as: “a design approach in which key design decisions are made with consideration of their anticipated effects on aspects of future project performance that are relevant to the project purpose and need. Thus, performance analysis becomes a tool to inform design decisions. Performance-based analysis enhances the exercise of design flexibility by documenting the anticipated performance effects of design decisions.” In addition, the Green Book introduces an expanded classification system for geometric design, including rural, rural town, suburban, urban, and urban core context classifications. A variety of guidance and examples is available to help practitioners apply performance-based design and consider context in the design process. This paper highlights recent research, as well as processes from Minnesota, Oregon, and Washington. It includes an example scenario to illustrate how performance-based design can be applied to generate, evaluate, and iterate alternatives for a roadway transitioning from rural to suburban development.