Description

This technical working paper details the second stage proposal in the development of the tire wear and consumption model for HDM-4 within the ISOHDM research framework. The paper focuses on the mechanical principles and force equilibrium equations that drive tire tread abrasion on asphalt, concrete, and unpaved road surfaces. It establishes the mathematical relationships connecting vehicle mass, longitudinal acceleration, lateral forces on horizontal curves, aerodynamic resistance, and surface macrotexture to the rate of rubber loss per vehicle kilometer traveled. Experimental test data from international research programs are analyzed to validate force coefficient values and assess the relative impact of road roughness (measured in IRI) versus microtexture and macrotexture on tread degradation. The paper addresses the differential wear rates observed across steer, drive, and trailer axles on heavy commercial vehicles, proposing multi-axle weighting factors to improve overall prediction accuracy. Furthermore, economic modeling aspects are explored, focusing on the trade-offs between initial tire purchase costs, retreading cycles, and premature replacement due to severe road surface distress. This document bridges early conceptual frameworks with the final mathematical code, providing highway engineers and software developers with an essential verification step for incorporating realistic tire operating cost calculations into highway planning models. Overall, the report emphasizes rigorous empirical validation, standardized data acquisition protocols, and modular integration into the broader Highway Development and Management analytical engine. By combining physical principles with statistical calibration across international trial sites, this working paper provides a robust theoretical and practical baseline for highway authorities to evaluate long-term infrastructure policy options,