Road-Damaging Potential of Measured Dynamic Tyre Forces in Mixed Traffic

A series of tests was conducted on a British trunk road in which the dynamic tyre forces generated by approximately 1500 heavy goods vehicles (HGVs) were measured using a load measuring mat containing 144 capacitive strip sensors. The data were used to investigate the relative road-damaging potential of the various classes of vehicles. Air suspensions were found to be more effective at static load equalization than steel suspensions. Two criteria were used to rank axle groups in terms of road damage: the average dynamic load coefficient and the 95th percentile aggregate fourth-power force. These criteria were found to rank axle groups in different orders, due to spatial correlation between tyre forces. On average, air suspended vehicles were found to generate smaller dynamic loads and hence less road damage than steel suspended vehicles. However, some air suspensions with inadequate suspension damping were found to generate very high dynamic loads and consequently very high levels of road damage.