Road surface influence on rolling resistance: coastdown measurements for a car and an HGV


The influence of road surface properties, such as macrotexture and unevenness, on rolling resistance and fuel consumption is an important factor to consider when deter¬mining the coating of a road surface. Results of a VTI study show that the effect of unevenness is in general significantly smaller than that of macrotexture.

The relative smallness of this influence makes measurements of it a challenging task. In literature a wide range of results can be found and there is still much confusion and uncertainty about how large the influence actually is. In this study, an attempt is made to obtain more reliable estimates of how macrotexture and unevenness affect rolling resistance. The primary method used here is the coastdown method. It has been applied to a private car and to a heavy goods vehicle (HGV). Concerning the effect of unevenness on rolling resistance, only the coastdown method provides any information. Results show that the effect of unevenness is in general significantly smaller than that of macrotexture.

The coastdown method provides, besides information about rolling resistance, other useful data for the vehicle, such as air resistance coefficients, temperature coefficients and transmission resistance.



ICTTP 2020

ICTTP, International Conference on Traffic and Transport Psychology, is held in Gothenburg, Sweden.



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