The influence of gross vehicle weight (GVW) and transport distance on timber trucking performance indicators – Discrete event simulation case study in Central Finland

Today, timber trucks of gross vehicle weight (GVW) up to 76 tonne are allowed to operate on Finnish roads from roadside landings to mills. Reducing trucking costs and exhaust gas emissions have been the dominant reasons for the increased GVWs of timber trucks. A discrete-event simulation (DES) method was used to compare the impact of the truck and payload size, trucking distance and timber assortment lengths on trucking performance indicators (e.g. productivity, energy efficiency and costs of trucking) in the procurement area of a case logistic company operating in Central Finland. The studied truck sizes were 68, 76 and 84t, of which the 76-t trucks dominate timber trucking in Finland. Over a transport distance of approx. 105km with an average assortment length of 4.2m, 76-t trucks had 9% higher and 12% lower productivity (m³/100km), 1% lower and 4% higher fuel consumption (l/m³) and 4% lower and 6% higher trucking cost (€/m³) compared to 68- and 84-tonner options, respectively. The improvement in regards to previous indicators was clearly bigger for the 76-tonner than the 68-tonner if the trucked wood assortments were lengthened to 5.0m. The differences in cost and fuel efficiency as well as annual trucking volumes were increased as a function of the trucking distance, when comparing the truck configurations with different GVWs and payloads. To conclude, the tendency of the size increase in GVWs in timber trucking in Finland can be justified in the light of the study results.