The goal of this project was to find a systematic relationship on how thick the structure above the sub-grade is in older roads in Sweden based on drill samplings. Based on the found relationships try to find an imaginative level of the sub-base and compare it with the real road construction using different dimensioning calculations using the computer programme called PMS object. After that comparing tensions and results between real and imaginative road structure and then see if it affects the necessary thickness of the asphalt layer. 615 samplings were analysed, and different parameters were compared with the depth to the sub-base. The parameters that showed the most promising relation was the average traffic per day per year and the thickness of the layers above the sub-layer, these two relations were then used as imaginative depths in the calculations. The relations found was then proven by the calculations to be not so accurate as imaginative thickness of the road construction. The difference of tensions and the sustainability of the road were too big. However, the calculations with the imaginative thickness were proven not to have a severe effect on the necessary thickness of the asphalt layers. / <p>Presentation redan utförd</p>