Trucks with non-conventional axle configurations are required to transport special loads. Criteria for the analysis of the effect of this type of vehicle in pavement structures are framed in the same principles of traditional vehicles. However, conditions that must be considered, such as higher loads levels, a greater number of wheels, possible overlapping of stresses, and lower speed of circulation, cause the use of equivalence factors to be a common practice. The dissipated energy approach is based on the calculation of a fundamental property of the structure, creating a variable independent of the load mode. This article presents a characterization of the dissipated energy in pavements under the effect of special trucks. Two types of vehicles with non-conventional configurations on a typical flexible pavement of the province of Quebec are studied. Using dissipated energy accumulation as a reference, critical points in the structure, as well as the effect of the magnitude of the load, are documented. An analysis framework based on dissipated energy offers a rational means for the study of pavements under unconventional loading conditions, and the accumulation of dissipated energy in the structure can be used as a reference for both the immediate effect of the vehicle pass and its influence on the remaining service life of the pavement.