The effect of traffic overloads on road pavements

Abstract

The road pavements are designed to support the expected traffic, mainly the heavy traffic that is defined by the maximum legal loads for their axles or by the actual axle loads corresponding to a specific load spectrum. These vehicles are considered in the pavement design by converting their effects through the use of truck factors which transform the damage they apply to the pavement to the damage that would be applied by a standard axle. The definition of the truck factors to convert trucks into standard axles or load equivalent factors to convert axles into standard axles is carried out by considering the maximum legal loads for each axle or considering the loads measured in weigh-in-motion systems corresponding to the actual loads. However, there is an important number of vehicles that travel with axle loads above the maximum legal limit. These axles cause significant damage to the pavements that reduces the pavement life and increases the rehabilitation cost. This paper investigates the impact of overloaded vehicles using two weight databases by studying the truck factors for different vehicle cases applied to different pavements. The study concluded that the presence of overloaded vehicles increases pavement damage and life cycle costs compared to the cost of the same vehicles with legal loads.