Assessment of Functional Performance and Cost-Effective Maintenance Strategies for Premixed Carpet Roads in Khajura Rural Municipality, Nepal

Abstract

Highway infrastructure serves as the backbone of economic development in developing nations like Nepal, where road networks facilitate trade, mobility, and social connectivity. However, the increasing volume of traffic coupled with heavy axle loads and environmental factors has accelerated pavement deterioration across rural road networks. This necessitates systematic maintenance strategies to preserve infrastructure investments. This study evaluates the functional performance of premixed carpet roads in Khajura Rural Municipality using the standardized Pavement Condition Index (PCI) methodology. Six representative road sections (R-1 to R-6) spanning 10–35km were rigorously assessed for distress types, severity levels, and density distribution. Comprehensive field surveys conducted from 2018–2023 revealed that Road R-5 exhibited exceptional performance with a PCI of 95 (“Good” rating), while Roads R-1 through R-4 and R-6 scored from 77–83 (“Satisfactory”). Predominant distress mechanisms included alligator cracking (up to 204m² in high severity cases), edge cracking (peaking at 115 linear meters), raveling (maximum 47.72m²), and potholes (up to 8.75m²). Based on PCI thresholds and life-cycle cost analysis, tailored maintenance strategies were proposed, demonstrating potential savings of 58–93% compared to conventional reactive rehabilitation approaches. The study underscores the critical importance of proactive, data-driven maintenance planning to extend pavement service life while optimizing limited municipal budgets in rural contexts. The methodology and findings provide a replicable framework for evidence-based road asset management in developing regions facing similar infrastructure challenges.