The Design of Flexible Surfaces by William S. Housel explores a rational methodology for designing flexible highway surfaces. Building upon the advancements in soil mechanics, the book aims to provide a logical, simplified approach to determining the necessary thickness of flexible surfaces that can distribute applied loads without exceeding the subgrade's bearing capacity. The key factors considered include applied loads, stress distribution, and subgrade bearing capacity. Detailed experimental data, pressure distribution theories, and mathematical formulations are presented to explain the interactions between tires, loads, and highway surfaces. With a focus on practical design, the book combines theoretical insights with empirical data, aiming to consolidate fragmented knowledge into a comprehensive design method.