Description

This paper investigates the modeling and calibration of HDM-4 pavement deterioration models for rural low-volume roads constructed under India's Pradhan Mantri Gram Sadak Yojana (PMGSY) program. Rural roads typically feature light pavement structures, thin bituminous surface treatments (such as surface dressing or premix carpet), and unique traffic profiles dominated by agricultural tractors, two-wheelers, and light commercial vehicles, alongside seasonal heavy agricultural transport. Standard HDM-4 models, designed primarily for high-volume arterial roads, frequently misestimate deterioration rates when applied to rural networks. The study monitored condition data (roughness, cracking, rutting, and edge break) across extensive rural road test sections over several seasons. The authors developed localized calibration factors for cracking initiation, moisture-induced distress, and roughness progression, accounting for local subgrade soil types (including expansive black cotton soils) and regional monsoon rainfall patterns. The calibrated rural road model demonstrates that environmental weathering and subgrade moisture variations exert a far greater influence on rural pavement degradation than traffic loading. The paper offers practical recommendations for asset managers to optimize rural road maintenance funding allocation, extend pavement service life, and schedule timely periodic renewals.