## 1 Introduction
[PERSON] in 2015 [5] analyzed the surface of forest roads affected by erosion, respectively conducted a case study in the Katamonu region of Turkey. The studied dependence factors were the gradient of the road slope and the density of trees in the analyzed area using GeoEye satellite images and a digital elevation model. [PERSON] and [PERSON] 2010 [6] studied the influence of the characteristics of forest road networks on the costs of chopping and chipping obtained in forestry operations in forest road areas. Costs have also been studied when extending/rehabilitation an existing forest road. [PERSON] et al. [7] considered some aspects of the impact of the realization of a forest road for log harvesting on the environment. In order to set up additional networks of forest roads, a geographical information system was used to evaluate the data obtained from the design of the new 16 secondary roads with minimal impact on the environment. [PERSON] et al. [8] measured road erodibility and showed that the surface material of the forest road had an erosion of 2.3 times higher than the fill slope of the road and of 1.3 times higher than the cut slope. Texture, bulk density, moisture content and organic matter from topsoil, cut slope, fill slope, and forest ground were determined for comparison. [PERSON] et al. [9] used the ground-penetrating radar method to detect the subsoil rock existing in the infrastructure of the forest road. A comparison between the existing forest road and the forecast for a new road was made successfully. [PERSON] et al. [10] started their study from the premise that in order to ensure the continuity of the log harvesting activity, the forest roads must be permanently open and stable. The paper correlated the size of the reconstruction of a forest road with the amount of precipitation, the volume of logs transported (especially high-traffic roads), and its maintenance. [PERSON] et al. [11] have studied the influence of forest roads on the habitat of deer in the area, by changing the routes of movement and feeding, the space used, and even mortality. In direct correlation with these, the effect of forest regeneration in the spring season was analyzed. It was observed that in the adjacent area to the forest road the density of undamaged trees was much higher than in the interior areas of the forest. [PERSON] et al. [12] made an exhaustive study of the main articles published in the period 2009-2019 regarding sustainable forest management in order to optimize the forest road traffic. It is specified the importance of forest roads, by allowing the harvesting, collection, and sustainable dispatch of some forest natural resources. [PERSON] et al. [13] developed some equations for estimating the density of the forest road network, before and after mechanization in a mountainous region of Japan. The operational efficiency and the costs for rehabilitating of the forest road network on an area of 6 hectares and a road density of 200 m/ha were also analyzed. [PERSON] et al. [14] dealt with the importance of forest road networks in extinguishing forest wildfires. The emphasis of the research was put on critical response time. The composition and dimensioning of the component layers of the road structures must be made in such a way as to be able to support the different intensities of traffic, in maximum tonnages or maximum number of trucks. The layers in the composition of a road system are four: the coating, the base layer, the foundation, and the foundation substrate. The clothing or the layer of wear and rolling protects the road structure against the action of atmospheric agents and are made of superior granular materials. The base layer has the role of reducing the concentrated compressive stresses transmitted by the clothing and distributing them to the foundation. The foundation receives the pressures transmitted by the base layer or, in its absence, by the clothing, reduces them even more, and distributes them to the forest bed.