Road traffic has a high variety of types of vehicles and cargo transported. One of the main difficulties in pavement design is forecasting the changes in traffic over time and evaluating the comparative deterioration power of the various loads with axle and tire settings and different levels of repetition. The road environment in Brazil, as we know, is the main means of the country's cargo transportation. Throughout the 1990s and 2000s the road modal accounted for over 60% of the total cargo transported in the country leaving the unbalanced Brazilian transport matrix with almost exclusive investments in such means of transportation.According to CNT 2012, which conducted a survey in approximately 45% of the paved network, evaluating the pavement functional conditions, traffic signs and geometry, 46% of the country's road network has some types of deficiency in the pavement. The goal of this work is to contribute to a better understanding of the complex influence of traffic in the design and service life of the pavement. The load pressure of commercial vehicle tires over the pavement has increased in recent decades. A more apparent effect of this increase in tire pressure would be the change in the pavement-tire contact area which in turn may result in an increase in the contact load between tire and pavement and other harmful effects on the structure. This study aims to determine the effect on the calculation of the N number, or the number of solicitations of the standard axle on the road pavement, measuring the overload as a percentage of the legal load indicated by a scale. Thus, we calculate how an increase in the overload percentage in comparison with the allowable load will influence the decrease of the calculated durability of the pavement designed for the highway.

The present work grants a study of technical development under a differentiated aspect where an extra tire was added to the standard double axle recommended by the Brazilian traffic calculation norms. The number N generated a triple axle, and a comparative study was made relating the balance load standardized in Brazilian balance laws for each type of axis and the damage generated on the pavement, measuring the results on a pavement chosen as a model, usually used on Brazilian highways. We verified through computer software, which uses the methodology of the theory of finite elements, supervised by the inspection bodies of the National Department of Transport infrastructure, proving if a larger amount of cargo generates the same damage to the pavement without jeopardizing its useful life, which was initially designed to last ten years.