Road Geometry vs. PCI in Different Pavement Surface Types

Abstract

Previous studies on the correlation between road geometry and pavement condition index have focused on flexible pavement types, which assume constant traffic volume in their modeling approaches. This creates limitations in understanding the behavior of different pavement types under varying traffic conditions and geometries. To address this gap, this study analyzes the relationship between road geometry and the Pavement Condition Index (PCI) across different surface types—specifically, flexible and rigid pavements—while including traffic volume as an independent variable. In Indonesia, road infrastructure is largely dominated by flexible pavements, with a total of 329,189 kilometers in 2024, compared to 218,908 kilometers of other pavement types, including rigid pavements. Reflecting this distribution, the study was conducted on six urban road sections, consisting of four flexible pavement roads and two rigid pavement roads. A non-linear regression approach was applied to develop separate models for each pavement type. The flexible pavement model achieved a coefficient of determination (R²) of 0.570, while the rigid pavement model produced an R² of 0.561. Among the geometry parameters evaluated, road gradient was found to be the most significant factor affecting PCI in both pavement types. Rigid pavement is recommended for roads with varying alignments to minimize geometry effects on pavement conditions, extending maintenance intervals and improving safety.