Potential energy savings by reducing rolling resistance of Dutch road pavements

The current study focuses on options to improve vehicle energy efficiency by reducing rolling resistance on Dutch national highways. Different studies of pavement materials have been evaluated, and models have been compared to experimental data to review rolling resistance indicators. The study shows that texture parameters MPD (mean profile depth) and RMS (root mean square) are relevant indicators for rolling resistance, whereas the effect of road roughness (IRI) is found to be larger than indicated in the evaluated models. The effects of other wavelength regions, texture orientation, and road wear need further investigation. The rolling resistance assessment shows that single-layer porous asphalt concrete (PAC) with aggregate size 6/16 (which is most currently used on Dutch highways) has rolling resistance levels that are 8-10% higher than the levels of double-layer porous asphalt concrete (DPAC) with aggregate size 2/6 Switching to DPAC 2/6 for highways would result in energy savings of 2-2.5%. These calculations are based on estimations and results with high uncertainty and should therefore be taken as a rough estimate of the potential energy savings. Further research is recommended to further refine and validate the results of this study.