Assessment of energy consumption of road due to rolling resistance
Résumé
Rolling resistance results from the energy dissipated by a tire rolling on a road surface. Accurate estimation of rolling resistance is important from an economical and environmental point of view considering the impact on vehicle fuel consumption. Until now, environmental assessment only focused on construction and maintenance works whereas recent studies showed that use phase can represent until 90% of the global energy demand of a road project. Thus, this study proposes to assess the impact of pavement surface characteristics (evenness with IRI and macrotexture with MPD) on environmental indicators (Energy total demand and Global Warming Potential) by considering both construction and use phase. Two fuel consumption models are selected for this research work. A 8.8 km length section on a French primary road is used as case study for this environmental assessment. The results show that more than 90% of energy consumption is due to the use phase when considering thirty years of pavement life. Moreover, an increase of IRI from 1 m/km to 2.5 m/km multiplies by three the annual energy consumption. In the same manner, a decrease of MPD from 1.2 mm to 0.8 mm represents a profit of more than 1.106 MJ/year. Equivalent results are observed on GWP. Thus, it is possible to diminish the environmental impact of a road project by changing the pavement surface characteristics with a boundary condition related to safety.