FINDING OPTIMAL ROUTES FOR NETWORKS OF HARVEST SITE ACCESS ROADS USING GIS-BASED TECHNIQUES

Many existing forest access roads are not simple independent paths des igned to access a single stand; rather they form complex networks of b ranching roads designed to access multiple stands. Traditional methods of finding optimal locations for these road networks have been almost entirely manual. This study developed and tested three GIS-based road network location strategies. A Monte Carlo approach was used to compa re the solutions generated by each of these strategies to optimal solu tions created through a complete enumeration approach. This analysis r evealed that a solution technique called branch evaluation required on ly a fraction of the time and produced results almost as efficient as those developed through complete enumeration. Branch evaluation was th en used to recreate actual road networks randomly drawn from the datab ase of roads in the Roosevelt and Arapaho National Forests. It was fou nd that branch evaluation was able to recreate routes similar to the a ctual road networks over 80% of the time. This relatively high matchin g rate implies that branch evaluation may be a useful tool for perform ing automated preliminary design of road networks.