Load-Sensitive Tire–Road Friction Modeling and Dynamic Stability Analysis of Multi-Axle Trucks

This study explicitly considers dynamic axle load transfer and load-sensitive tire–road friction characteristics in estimating the safe speed of multi-axle trucks negotiating curved road segments. Conventional standards, which assume a constant friction coefficient, fail to capture wheel-specific load variations and tend to underestimate rollover and skidding risks. To overcome these limitations, a load-sensitive friction model is integrated with the friction ellipse and the static rollover threshold (SRT), and a forward–backward pass is applied to compute dynamically feasible speed trajectories. The framework was demonstrated through accident reconstruction of a curved ramp rollover scenario using TruckSim–Simulink co-simulation based on reported geometric and vehicle parameters. The results show that ignoring load sensitivity systematically overestimates safe speeds and underestimates lateral deviations. Moreover, variations in the SRT level demonstrated the trade-off between structural stability and frictional constraints, with rollover dominating at lower stability and skidding at higher stability. These findings highlight the necessity of incorporating dynamic load distribution and load-sensitive friction into truck safety speed estimation. The proposed framework provides a foundation for speed control strategies in autonomous trucks and for improvements in road design standards, with potential for enhanced applicability when combined with emerging real-time friction estimation and load measurement technologies.