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Smooth movement of vehicles on forest roads necessarily requires widening of the traveled way in small radius curves. This paper presents the results of a comparison of two methods for determining the required widening of a forest road traveled way in small radius curves: the traditional method based on formulas and the traces curve method, obtained by simulating the movement of vehicles. Both methods were applied in the preparation of the Main project of reconstruction of the forest road “Rasadnik - Pustinac” with a length of 5.285 km in the teaching base of the Faculty of Forestry “Majdanpečka domena”. In the project which determined the traveled way widening by the traces curve method, the total area of the surfacing was by 2.79% smaller than the area of the surfacing in the project which determined the widening using a formula. The width of the traveled way directly affected the scale of earthworks. In the first case, the volume of the cut was by 4.17% lower than in the second one. The volume of the filling decreased by 7.05%, and the amount of material needed for making the surfacing decreased by 2.94%. A smaller volume of earthworks and material required for pavement construction in the preparation of the Main project of reconstruction, in which the size of widening was calculated by the traces curve method, influenced the estimated value of reconstruction is lower by 3.34% than the total cost of reconstruction obtained in the preparation of the Main project of the same forest road reconstruction that calculated the widening size using the traditional method.

This paper presents a new method of half serpentine marking in constructing forest roads on the terrain itself. This method is based on surveying the elements needed for half serpentine marking on forest roads and on estimating other needed elements and their finished marking. By using this method construction errors are reduced as well as the number of attempts of half serpentine marking. In the way, the effects of half serpentine marking are increased compared to the ones reached by the method used so far.

One of the three studied variant solutions of forest road conceptual design was selected based on the linear distribution of criteria, as the method of multicriteria optimization. The selection was performed with 25 parameters classified as economic, technical, production and social criteria. The parameters of technical criteria were grouped into design, construction and building parameters. Based on calculated nominal values of parameters by the given criteria, their ranking, comparison, point rating and scoring, the selected most favorable solution was variant 1.

This paper presents a new method of symmetric serpentine marking in constructing forest roads on the terrain itself. This method is based on surveying the elements needed for symmetric serpentine marking on forest roads and on estimating other elements and their marking. By using this method construction errors are reduced as well as the number of attempts of serpentine marking on the terrain itself. In the way, the effects of serpentine marking are increased compared to the ones reached by the method used so far.

The dependence of the scope of production of the definite forest products (total felling volume, round wood, cordwood, felling waste, waste percentage) in Serbia was analyzed for the period 1991-2000, in relation to the changes of forest road network density. It was concluded that, with the change of forest road network density, the total felling volume, round wood and cordwood decreases, while the quantity of felling waste and its percentage in the total production are not in correlation. This is opposite to the expected which points to the paradox in these relations in the study period.

Regulation works in small torrential streams disturb the natural flow regime and the structure of banks and riparian area. The streams are crossed by bridges and culverts. However, at places of low traffic intensity, natural fords are often used for crossing. A regulated ford is constructed by lining and protection of the natural ford, where due to reduced roughness in the ford zone, hydraulic characteristics of the stream show a series of specificities This paper presents the method of calculation of hydraulic factors, which determine the conditions of regulated ford. The construction of regulated ford, as a civil engineering structure, is designed in the conditions enabling a safe traffic at low and medium discharges, while at high water levels there are no obstacles to the flow of water and torrential sediment .

Accurate presentation of natural land forms directly affects the accuracy of earth volume calculation, the component of technical documentation of the forest road master project. Consistent to legal provisions, forest road master project is characterised by high accuracy of the planned scope of works compared to the realised scope of works, which should amount to ±3%. The volume of earth material is calculated based on the road cross-sectional area and the distance between the cross sections. The accuracy of the area of cross sections depends on the accuracy of land form presentation Accurate presentation of natural land forms depends on a great number of factors, the most significant of which are the methods of surveying and acquisition of data necessary for land form presentation, preciseness of equipment and instruments used in surveying and acquisition of data, and the method of land form presentation. The accuracy of earth material volume calculation depends on the method of computation, method of presentation of natural and artificial cross sections, and the phase of design. The presentation of natural land form in the width occupied by roadway cross section depends on the validity of the obtained station point elevation (Ht) and the elevations of detailed points (Hi). A relevant factor of the accuracy of cross sectional area, compared to its other elements, is the accuracy of the depth of cut or the height of fill (h) which should agree with the required accuracy, i.e. the adopted tolerance of the earthwork bill of quantities deviation up to 3%.

This paper presents a multi-criteria selection of the best forest road network with the aim of achieving effective preventive and timely repressive protection against forest fires. The research was carried out in national park (NP) “Tara” at a site which is under constant threat of fire. Four variants of the forest road network were designed and analyzed against seven criteria, and the best variant was selected using entropy weight coefficients (EWC) method. The importance of these seven criteria was studied by the management of the NP “Tara.” The greatest importance was given to the criteria relating to the cost of construction and maintenance of permanent and temporary roads (47% of the total value of all criteria). The EWC method did not select the variant based on the lowest costs of construction and maintenance as the best option, but the variant whose location was the most suitable for effective defense against forest fires. [ABSTRACT FROM PUBLISHER]