An optimization approach to design forest road networks and plan timber transportation

The provision of ecosystem services depends on the landscape-level distribution of forest management options over extended planning horizons. Nevertheless, transportation costs are an important fraction of total procurement costs. Therefore, forest managers are challenged by the need to make decisions regarding the design of the road network needed to have access to forest management units (e.g., stands) as well as the transportation of forest products over this network. The objective of this research is to develop an approach to integrate the design and maintenance of a forest roads' network and to provide solutions to the timber loading location site and the timber transportation problems. The emphasis is on the combination of mathematical programming formulations and heuristic solution techniques to minimize the sum of road building, road maintenance, timber loading and transportation costs. Specifically, a mixed integer programming model is built to represent the problem while a heuristic algorithm, based on a Graph Simplification procedure and a big-M Estimation procedure, is proposed to solve the underlying optimization problem. Results from an application to a large-scale forest management problem in Northwest Portugal involving 1137 management units are discussed. Results suggest that this approach may help address efficiently the need by forest managers to integrate road design, road maintenance, timber loading location and transportation concerns.