Wood transportation costs have significant impacts on timber investment returns. To optimize transportation costs, a practical design of the route network is necessary for log trucks that ship wood material from timberlands to wood mills. Road conditions resulting from various road maintenance policies dramatically affect speed limits, log-truck route networks, and transportation costs. The effects of road maintenance policies on truck route selection and user/agency cost trade-offs have not been deeply researched. By considering forest-road maintenance policies, this study intends to provide accurate information on timber-processing service coverage and log-truck route selections for forest companies or subcontracted fleets of log trucks. This research also conducts an environmental analysis to assess the effects of various road maintenance policies on consumed energy and greenhouse gas emissions of log trucks. With current maintenance policies, the results indicate that only between 33% and 51% of timber areas in Oregon can be accessed or harvested by existing nearby wood mills. However, application of the proposed road maintenance policy in this paper would increase accessibility to timberlands by up to 104%. The cost of log transportation also decreases by 16%–34%. The methodology developed in this study can lead to improvements in forest road preservation management systems to achieve the full benefits of reducing log-truck emissions and total transportation costs.

Background: Due to the growing demand for energy and environmental issues related to using fossil fuels, it is becoming tremendously important to find alternative energy sources. Bioethanol produced from switchgrass is considered as one of the best alternatives to fossil fuels. Methods: This study develops a two-stage supply chain modeling approach that first determines feasible locations for constructing switchgrass-based biorefineries in the state of North Dakota by using Geographic Information Systems (GIS) analysis. In the second stage, the profit of the corresponding switchgrass-based bioethanol supply chain is maximized by developing a mixed-integer linear program that aims to commercialize the bioethanol production while impacts of energy use and carbon emission costs on the supply chain decisions and siting of biorefineries are included. Results: The numerical results show that carbon emissions and energy consumption penalties affect optimal biorefinery selections and supply chain decisions. Conclusions: We conclude that there is no need to penalize both emissions and energy use simultaneously to achieve desirable environmental benefits, otherwise, the supply chain becomes non-profitable. Moreover, imposing emissions or energy consumption penalties makes the optimization model closer to supply sources while having higher land rental costs. Such policies would promote sustainable second-generation biomass production, thus decreasing reliance on fossil fuels.

Renewable jet fuel (RJF) production has been recognized as a promising approach for reducing the aviation sector’s carbon footprint. Over the last decade, the commercial production of RJF has piqued the interest of airlines and governments around the world. However, RJF production can be challenging due to its dispersed supply resources. Furthermore, the production of RJF is more costly compared to producing conventional jet fuel. In this study, using a mixed integer linear programming (MILP), we design a corn-stover-based RJF supply chain network in which we obtain an optimized configuration of the supply chain and determine operational decisions required to meet RJF demand at airports. To accelerate the commercialization of RJF production, we examined four incentive programs designed to cover the supply chain’s costs, with agricultural statistics districts serving as the designated supply regions. This study is validated by employing the model to design the supply chain in the Midwestern United States. The results from this study are promising as they show the supply chain can achieve commercialization with partial financial coverage from the incentive programs. Based on the findings of this study, policymakers can devise policies to commercialize RJF production and accelerate its adoption by the industry.