Brief: Overview of Performance-Based Practical Design (PBPD)
State Departments of Transportation (DOT) are increasingly challenged with addressing their system performance, mobility, and safety needs in the current era of financial limitations.
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.
- PBPD focuses on performance improvements that benefit both project and system needs.
- Agencies make sound decisions based upon performance analysis.
- By scrutinizing each element of a project's scope relative to value, need, and urgency, a PBPD approach seeks a greater return on infrastructure investments.
- PBPD strengthens the emphasis on planning-level corridor or system performance needs and objectives when planning, scoping and developing individual projects.
- PBPD can be implemented within the Federal-aid Highway Program regulatory environment utilizing existing flexibility. PBPD does not eliminate, modify, or compromise existing design standards or regulatory requirements.
Keys to Successful State Implementation of PBPD
- State DOT executives embrace PBPD and communicate this support to all State employees and consultants.
- State DOT PBPD champion leads implementation throughout all levels of the agency.
- Agencies revise policies and guidance as appropriate to include the values of PBPD, thus securing a multi-disciplinary and comprehensive approach to delivering projects under PBPD.
- Agencies encourage and empower engineers to exercise judgments on projects based on PBPD principles.
- FHWA Division Offices support State DOT's in their implementation with early and close coordination.
Recommended FHWA Role
Implement FHWA Strategic Implementation Plan PY 2015 National Initiative 5.1 (Raise awareness of the concept of performance-based practical design) as follows:
- Collaborate with AASHTO on evolving the design process.
- Support each State's PBPD interests.
- Promote use of existing design flexibility along with performance analysis tools.
- Develop and disseminate informational resources, including:
- Questions and Answers
- Case studies
- Web site
- Promotional materials
- Technical Assistance