Optimising truck platooning configurations for enhanced pavement performance across diverse climatic zones: a generalised additive mixed model approach

Truck platooning can improve freight mobility, fuel efficiency, and traffic operations. However, closely spaced truck movements may accelerate pavement deterioration by concentrating repeated axle loads and reducing pavement recovery time. This study evaluated the effects of truck platooning on flexible pavement performance across four representative U.S. climate zones using AASHTOWare Pavement ME Design simulations and generalized additive mixed models (GAMMs). Platoon sizes from 2 to 5 trucks and inter-truck spacings from 10 to 80 ft were analyzed. Four distress measures were evaluated: terminal International Roughness Index (IRI), total permanent deformation, asphalt concrete (AC)-only permanent deformation, and AC bottom-up fatigue cracking. Climate-specific GAMM response surfaces captured nonlinear relationships among platoon size, spacing, climate, and pavement distress. Results showed that inter-truck spacing was the dominant platooning-related factor, with the highest sensitivity observed for bottom-up fatigue cracking. Short spacings, particularly below 20–25 ft, caused fatigue cracking that reach 100% in several configurations, whereas increasing spacing toward 50–70 ft substantially reduced predicted distress. Larger platoons increased all distress responses, especially fatigue cracking. Wet-freeze climates generally produced the highest rutting, roughness, and fatigue responses. Overall, the findings indicate that climate-aware limits on platoon size and moderate inter-truck spacing can substantially reduce pavement damage.