This article gives an overview and analysis of the works aimed at finding empirical dependencies linking the indicators of longitudinal and transverse evenness with the parameters of the deformability of road constructions and its individual elements. We list the data of field experiments and laboratory studies of triaxial deformation of materials by a repeatedly applied load. The methods of calculating the deformation based on rheological models, including the theory of hereditary creep, have been analyzed. The results of studies substantiating the acceptable and the critical individual irregularities formed in the longitudinal and transverse directions are discussed. A new method of calculating the acceptable depth of irregularities, allowing for the characteristics of the vehicle, including the time of contact interaction between the wheel and the pavement that depends on the speed of the vehicle, has been suggested. The proposed method of calculating the critical values of irregularities ensures the required level of consumer characteristics (i.e. speed and traffic safety) over the whole lifetime of the road structure.