Validation of Performance-Based Design-Phase 2
Performance-based design (PBD) is a renewed approach for project decision-making to specifically address the purpose and needs of projects by providing design flexibility. A PBD approach may be implemented for specific long- and short-term performance goals of a project, a whole corridor, or the overall system. PBD is not limited to geometric design elements; it spans project planning decision-making to identify the type of facility, to selection of design volumes, to design speed, and even to the selection of pavement materials and thickness.
Validation of PBD will consist of comparing safety surrogates observed in study/control sites and determining if PBD sites experienced equal or lower safety performance than control sites that comply with design standards. Time series data available in the Strategic Highway Research Program 2 Naturalistic Driving Study (SHRP2) NDS Trips database provide vehicle kinematic measures at different points (in time and location) that will be linked to the curved roadway segment geometric elements (radius, lane/shoulder width). These kinematic measures will then be used as safety surrogates to determine safety performance based on thresholds of observed behavior, frequency, distribution, and risk. Additionally, SHRP2 NDS event data will be collected for every site to evaluate crashes and near-crash events. Observed crash data from corresponding jurisdictions will also be collected for the sites under study. The different sources of data (trips, events, and observed crashes) will be used to conduct separate statistical analyses based on the properties and probability distribution of the data to quantify the difference in safety performance between sites with PBD criteria and conventional design standards.
- Safety Training and Analysis Center (STAC)
- Safety Design and Operations
- Naturalistic Driving Study Pooled Fund