Assessing Asphalt Pavement Microsurfacing Texture and Skid Resistance Analysis via Image-Based Techniques

Skid resistance is a key factor affecting pavement safety, particularly under wet conditions where the risk of hydroplaning increases. This study investigates the relationship between pavement surface texture and skid resistance of microsurfacing, a widely used preventive maintenance treatment, on the Tehran–Qazvin Highway, Iran. Surface texture was characterized using the conventional volumetric sand patch method and a low-cost two-dimensional photogrammetry technique based on a standard digital camera. The evaluated texture parameters included Mean Texture Depth (MTD), pixel-based threshold segmentation (dark and light surface areas), and surface area ratios. Skid resistance was measured using the British Pendulum Tester and expressed as the British Pendulum Number (BPN).

The results revealed a strong and statistically significant linear relationship between MTD (0.45–0.75 mm) and BPN (R² = 0.9976), indicating that macrotexture is the primary factor governing skid resistance in the investigated microsurfacing. This high correlation is attributed to the relatively uniform aggregate gradation, binder distribution, and controlled field conditions of the test sections, which minimize surface variability and enable MTD to serve as a reliable indicator of friction performance. In contrast, the correlation between BPN and the dark area percentage was substantially weaker (R² = 0.3076), suggesting that image intensity alone cannot adequately characterize pavement friction because it is influenced by aggregate mineralogy, binder distribution, and localized surface wear.

The proposed image-based photogrammetry approach provides a rapid, cost-effective, and non-destructive alternative to conventional texture measurement techniques, eliminating the need for specialized laser-scanning equipment while maintaining high accuracy for microsurfacing applications. The findings demonstrate the potential of this method for large-scale pavement condition monitoring, skid resistance assessment, and maintenance decision-making by highway agencies.