A proposed performance-based highway design process: incorporating safety considerations

摘要

The current highway design practice in the United States allows for flexibility in application of geometric design principals, however, lacks a formal methodology resulting in varying degrees of application by region, agency and individual. While the consequences of design flexibility (i.e., construction cost, capacity, highway safety, etc.) are recognized, an improved method of quantifying and comparing the consequences of design decisions is needed to allow for more informed decision making. This paper proposes a performance-based design process which can be implemented using the tools, research and published design documentation that exists within the highway engineering community. This process capitalizes on existing workflow for increase acceptance among professionals. Implementation will lead to an improved understanding of the impacts to safety and other outcomes caused by relaxing design standards to accommodate existing ROW, environmental constraints, and other items traditionally viewed as constraints. It is the objective of this paper to present a proposed performance-based highway design process demonstrated using highway safety as the measurable outcome. The proposed process can be extended to include other highway engineering performance outcomes such as vehicle capacity but this paper focuses solely on the safety performance of highway alternatives.