Abstract
The Indiana Department of Transportation (INDOT) utilizes the International Roughness Index (IRI) and Falling Weight Deflectometer (FWD) data to prioritize pavement maintenance across interstates, state roads, and U.S. highways. While IRI measures ride quality and FWD assesses structural integrity, their threshold values vary by road type, reflecting differing service expectations. Effective pavement maintenance requires a holistic approach, combining surface condition data from IRI with structural insights from FWD through predictive modeling. Additionally, these metrics should not only estimate service life but also provide indications of potential distress types, ensuring a comprehensive understanding of pavement performance and maintenance needs. The study employs a dual methodological approach, combining probabilistic and deterministic modeling techniques to evaluate pavement deterioration and predict performance across various road classifications. A Markov chain probabilistic model is utilized to analyze deterioration rates and assess the likelihood of pavements transitioning between condition states (e.g., very good to poor) for each road category. In parallel, an empirical deterministic approach is applied to develop IRI-based prediction models, enabling cross-comparison of degradation trends and steady-state conditions derived from both methodologies. The deterministic approach further investigates the influence of initial IRI on pavement performance, emphasizing its critical role in maintaining functional performance within acceptable limits. Additionally, the remaining service life and life expectancy of pavements are estimated to establish terminal failure thresholds for different road categories. Finally, the study analyzes FWD data from various roads to predict maintenance priorities by establishing a correlation with IRI. The outcome of the study is the expected use of IRI and FWD data to support INDOT’s commitment to proactive pavement maintenance.
Keywords
falling weight deflectometer (FWD), international roughness index (IRI), Markov chain modeling, pavement service life
Report Number
FHWA/IN/JTRP-2025/13
SPR Number
3902
Sponsoring Organization
Indiana Department of Transportation
Performing Organization
Joint Transportation Research Program
Publisher Place
West Lafayette, Indiana
Date of Version
2025
DOI
10.5703/1288284317877
Recommended Citation
Khajehvand, M., Mamun, A. A., Nantung, T., & Cho, S. (2025). Performance acceptance and performance monitoring of pavement using Falling Weight Deflectometer (FWD) and International Roughness Index (IRI) (Joint Transportation Research Program Publication No. FHWA/IN/JTRP-2025/13). West Lafayette, IN: Purdue University. https://doi.org/10.5703/1288284317877
SPR-3902 Technical Summary
INDOT Pavement Preservation.pdf (5940 kB)
FHWA 2010 Report