Performance-Based Practical Design
Issue
State Departments of Transportation (DOT) are increasingly challenged with addressing their system performance, mobility, and safety needs in the current era of financial limitations.
Summary
The Federal Highway Administration (FHWA) conducted an in-depth review of the Practical Design concept, including interviewing a number of States about their practices.
Though the name, definition, and approach of Practical Design vary from State to State, most States with a Practical Design program emphasize a renewed focus on scoping projects to stay within the core purpose and need. By exercising a greater level of discipline, agencies may eliminate nonessential project design elements resulting in lower cost and improved value. This approach enables States to deliver a greater number of projects than otherwise possible under their previous project development approaches. By implementing Practical Design, States realized cost savings by utilizing flexibility that exists in current design guidance and regulations.
A concern is that agencies may overemphasize short-term cost savings without a clear understanding of how such decisions could impact other objectives (such as safety and operational performance, context sensitivity, life-cycle costs, long-range corridor goals, livability, and sustainability).
To address this concern, agencies can make more informed decisions by evolving towards a Performance-Based Practical Design (PBPD) approach grounded in a performance management framework. PBPD can be articulated as modifying a traditional design approach to a "design up" approach where transportation decision makers exercise engineering judgment to build up the improvements from existing conditions to meet both project and system objectives. PBPD uses appropriate performance-analysis tools, considers both short and long term project and system goals while addressing project purpose and need.
Read more in our Brief: Overview of PBPD.
This web site provides resources to assist agencies in considering Performance-Based Practical Design: