2.4.1 What is Performance Based Practical Design?
What is PBPD? | |
What PBPD is: | What PBPD is not: |
Grounded in performance management | New regulation or requirement by FHWA |
Exercises engineering judgement to address a project’s purpose and need | New version of Value Engineering (VE) |
Uses appropriate performance-analysis tools | Replacement for Context Sensitive Solutions (CSS) |
Considers both short- and long-term project and system goals | Opportunity to disregard long-term needs |
- | Compromise on safety or user needs to save money |
Performance Based Practical Design (PBPD) is the process of performance evaluations, as previously discussed in
, during project development to guide alternative selections and, ultimately, geometric design decisions. PBPD modifies the traditional dimensional design approach to a “design up” approach – using engineering judgement and practical design to build up the improvements from the existing conditions to meet both project and system objectives.
PBPD is an approach to decision-making that encourages engineered solutions rather than reliance on maximum values or limits found in design manuals. PBPD is making practical decisions but making sure those decisions are based on an objective analysis of the relevant data.
FHWA discusses notable attributes of PBPD to be:
- 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 Used In All Phases Of The Project Lifecycle | |
Planning | Preliminary Engineering & Design |
Define system and project purpose and need | Start with existing conditions as the baseline |
Develop concise project objectives from the purpose and need | Engineer solutions that meet the purpose and need – not just meet standards |
Consider project in the context of the system | Evaluate tradeoffs based on objective analysis of data |
Address all users | Support with design exceptions if needed |
- 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.
- PBPD should consider multiple design and operating solutions to find the combinations that best addresses the project objectives.
Additional guidance on PBPD and Benefit/Costs Analyses can be found in the
. Examples of PBPD can also be found in the following references:
- FHWA PBPD case studies;
- Demonstrating Performance-Based Practical Design through Regional Performance-Based Planning – Federal Highway Administration (FHWA);
- Demonstrating Performance-Based Practical Design through Alternative Intersections – Federal Highway Administration (FHWA);
- Demonstrating Performance-Based Practical Design through Analysis of High-Occupancy Toll Lanes – Federal Highway Administration (FHWA); and
- FHWA-HIF-16-030 - Federal Highway Administration (FHWA).