Comparing Network-Level Structural Measures Impact on Asphalt Pavement Performance Models

Abstract

Incorporating structural measures into pavement management systems can enhance the underlying performance models. The traffic speed deflectometer (TSD) offers advantages for network-level testing, but it differs from the traditional falling weight deflectometer (FWD) as a structural measure. It is important to investigate which measure provides the most improvement in pavement performance models. This study compares the impact of four structural measures on pavement performance models of four distress rating dependent variables (cracking, rutting, load distress rating, and critical condition index). Structural measures from the Virginia Department of Transportation pavement management data were analyzed, including ground penetrating radar measure of asphalt thickness, FWD measure of structural number, TSD measure of surface curvature index (SCI), and the site’s pre-treatment rate of deterioration. A multilevel model approach related each structural measure to site-specific performance models of asphalt resurfacing treatments. The TSD measure of SCI demonstrated the greatest impact on the cracking, load distress rating, and critical condition index models with increases in marginal R² of 0.05, 0.03, and 0.01, respectively. Pavements with higher SCI values reach a failing critical condition index threshold one year sooner. Incorporation of the TSD measure of SCI leads to improved performance models and will benefit pavement management systems.