2015 - USA - Relationship Between Dynamic Axle Load, Roughness and Fuel Consumption

The objective of the study described in this paper is to investigate a mechanistic relationship between roughness and Fuel consumption (FC). First, simulations of the response of a 5‐axle tractor‐semitrailer (5A‐Semi) to real profiles with different roughness levels were performed to estimate the dynamic axle loads induced by each profile. Then, the Dynamic Load Coefficient (DLC) was computed every 0.03 km (0.02 miles). Finally, the FC of the truck was calculated and the recent HDM 4 model from the NCHRP 1‐45 project was re‐calibrated using DLC instead of the International Roughness Index (IRI) for each 0.03 km (0.02 miles) subsection. The analysis shows that the new model, after appropriate calibration, adequately predicted the effect of roughness on FC of the 5‐axle Semi. Statistical analysis showed that there is no difference between the observed and the estimated FC at 95 percent confidence level.