The use of woody biomass has received considerable attention for energy production. However, high production and transportation costs can be a barrier to woody biomass use in some regions. Developing cost-effective transportation systems has become an economically critical issue to expand biomass use. We developed a computer model, named BIOTRANS, to estimate biomass transportation productivity and cost in western Oregon. We used BIOTRANS to evaluate the effects on transportation costs of six different truck configurations, four transported material types, and over 100 travel routes. Different truck configurations, transported material types, and travel route characteristics were found to significantly affect transportation costs. A four-axle truck and single trailer was the most cost-efficient hauling configuration for the conditions studied, and shavings had 30 percent higher trucking costs than other hog fuel, chips, and sawdust.