Determination of the Safest Route for Logging Trucks based on Road Types and Conditions

Hauling of wood-based forest products is a complex problem that requires evaluation of many alternative routes. The forest transportation has been generally done by using logging trucks with high carrying capacity. The logging truck driving is one of the dangerous occupations in forestry, particularly in Turkey where forest lands are mostly located in mountainous regions with steep slope. The safety risk of truck driving mainly depends on the road standards and conditions. The majority of the forest roads in Turkey has low standards that limit the maneuverability of logging trucks. In such conditions, forest transportation should be planned by considering not only transportation costs but also safety of logging truck driving. In this study, GIS-based network analysis method was used to develop the optimum transportation plans for two scenarios. In the first scenario, optimum plan that minimized the total transportation cost was developed while transportation plan that ensured the safest logging truck driving was optimized in the second scenario. The safety score was assigned to each road section based on the road type (asphalt, gravel, forest road) and road conditions (good, medium, poor). In the study area, located in the city of Bursa in Turkey, there were three forest depots and five landings. The results indicated that the transportation cost increased by %15.76 when the safety of logging truck driving was prioritized. In this scenario, forest products from three landings were transported to different depots, compared to the first scenario. In order to ensure safe driving of logging trucks, forest roads should be properly reconstructed and regularly maintained considering the technical and safety requirements. Although reengineering of the forest roads requires some investment, improved forest roads will provide better access to forest resources for many forestry activities such as reforestation, protection, management, logging operations, and recreations.