Pavement Deformation Impact on Energy Loss and Vehicle Rolling Resistance

Concern in fuel conservation and carbon foot print reduction has generated a special interest in the mechanics of vehicle pneumatic tires rolling resistance. It is well known that rolling resistance between vehicle tires and pavement surface is one of the major loss mechanisms of the vehicle’s generated power. The primary aim of this paper is to evaluate the contribution of the pavement’s structural characteristics to rolling resistance. Several studies have focused on determining the vehicle rolling resistance primarily based on vehicle interaction with the pavement surface without quantifying the effect of pavement deflections on this parameter. This study focuses on isolating the pavement deflection component to quantify its influence on the rolling resistance. In order to achieve this goal, several thousand Falling Weight Deflectometer (FWD) test points were evaluated. A total of nineteen projects across the US were selected for this evaluation. Those projects included pavements located in different climatic regions, and having different pavement types, layer thicknesses, functional classifications, and traffic levels. The results indicate that the energy loss during an FWD test can be determined reasonably well from the deflection under the load for the wide range of evaluated pavement structures. In addition, the deflection component of rolling resistance can be estimated from the energy loss. Quantifying the impact of pavement stiffness and traffic-induced pavement deformations on rolling resistance can lead to the design and construction of pavement structures with lower rolling resistance, which in turn will reduce the carbon footprint of the nation’s highways.