Measurement of fuel consumption on asphalt and concrete pavements in Sweden

In order to increase knowledge of how fuel consumption corresponds to pavement type, the Swedish National Road and Transport Research Institute (VTI) was commissioned to investigate the difference between asphalt and concrete pavement surfaces. Measurements were made north of Uppsala, Sweden; where a motorway section included both types of pavement. Prior to the measurements, a pilot study was conducted to calibrate the methodology and to get an initial idea of possible differences between the two pavements. The trials indicated that there was a difference and this led to the initiation of the full scale study. It was concluded that differences were related to differences in pavement surface texture. A Road Surface Tester (RST) vehicle was used to investigate these properties (i.e. Mean Profile Depth, MPD). These measurements revealed that the two pavements were more or less identical in terms of slope gradient along and across the lanes, while the asphalt pavement had rougher macro texture (MPD) than the concrete pavement. The measurements showed 1.1 % less fuel consumption on the concrete pavement compared to the asphalt pavement. These results were statistically significant according to a t-test. The difference is mainly attributed to differences in macro texture. In summer 2009 initial fuel measurements were made with a Heavy Goods Vehicle (60 tons), Scania R500. The results show that the difference in fuel consumption could be even bigger for heavy vehicles than for cars, especially in hot summer days when the stiffness of asphalt pavements is low.