Relationship between driving conditions, pavement surface characteristics and rolling resistance

Rolling resistance is a physical phenomenon related to the dissipation of energy that occurs during the passage of a tire on a road pavement. This loss of energy generates forces opposed to the vehicle movement, which in turn increase fuel consumption and CO2 emissions. Rolling resistance can represent until 30% of the resistive forces depending on the vehicles’ characteristics and driving conditions (rural or urban roads, motorways). Previous studies identified the main influencing factors related to the vehicle (i.e. tire pressure, load, speed, temperature) and pavement (texture, roughness). Nevertheless, the influence of the driving conditions is less known. This paper presents a study performed at the University Gustave Eiffel’s test track which explores the impact of vehicle speed, tire pressure and gearbox ratio on rolling resistance. The test track combines a banked corner 1300 m long with a straight section of 1000 m, paved with twelve different pavement surface mixtures exhibiting various microtexture and macrotexture levels. A passenger vehicle was instrumented with various sensors to measure its dynamical behavior (speeds, accelerations), the forces and torques applied to the wheel and the driving commands (gearbox ratio, engine speed, steering wheel angle). A wide experimental test plan was performed to collect data at a frequency of 100 Hz, which was posteriorly post-processed to filter noise. Finally, a statistical analysis was carried out to assess the impacts of tire pressure and engine speed on rolling resistance forces. Variations of the rolling resistance forces between 2 and 10% were observed depending on the vehicle speed and pavement surface texture.