A method for simplifying irregular ground profile of roadway cross sections by a straight line is presented. The presented method does not affect the accuracy of earthwork volume computations. Two types of cross sections are considered: cut (or fill) and transition sections. For a cut (or fill) section, the simplified section is designed such that its area equals that of the original section. This is accomplished by adjusting the least-squares (LS) parameters. Three cases of adjustments that depend on the area of the original section and the unadjusted LS parameters are presented. These cases preserve the section type (cut or fill) and, as much as possible, the general shape of the original section. For a transition section, the simplified section is designed such that its cut and fill areas equal those of the original section. These conditions of equal areas are used to develop formulas for designing the simplified section directly. Application of the method is illustrated by numerical examples. Key words: roadway, cross section, irregular, least squares, linear profile, earthwork volume.