Abstract
Forest roads are characterized by low traffic, but heavy timber haulage trucks have a significant influence on road conditions and usually exceed the limit of 80-100 kN per axle. The excessive weight of the trucks degrades the road surface and the forest environment. This article presents the results of a study of timber transport loads from their places of acquirement (forest districts) to the recipient (a large sawmill). The analysis includes the parameters of the timber transport vehicles and focuses especially on the gross vehicle weight (GVW), the total weight of empty truck and trailer during transport, and the weight of their loads. Scania, Iveco, Man, and Mercedes trucks with trailers and semitrailers designed for large-size pine timber transport were analyzed. ANOVA results revealed that all 80 analyzed vehicles exceeded the permitted GVW in the range from 2.28 to 19.94 Mg, transporting from 20.1 to 37.5 m3 of timber. The coefficient of determination between the amount of hauled timber and the GVW equaled 62.7%. Research conducted previously concluded that forest roads with ground and gravel surfaces are not suitable for overloads of 120-150 kN per axle. Therefore, it is necessary to find a logistical solution that will allow the load volume to be maintained at an acceptable level without destroying the forest road surface.