This paper reviews the environmental impacts of forest roads at the on-site and the watershed scale. The components of a road prism--the cut slope, ditch, running surface, and fill slope--are defined and a description of the infiltration and flow processes are made for both insloped and outsloped roads. The perceived advantages of both are discussed. Flow on the road prism without traffic and a long-term study of the sediment production also follow. Some of the differences in sediment production between traffic and no-traffic conditions are highlighted, and the results of three studies of sediment production from roads with traffic are also discussed. Two methods to mitigate the impact of road traffic are reviewed. At the watershed scale, two studies that used the same data, but reached opposing conclusions are discussed. There is also a review of a study investigating the connection of a road system and stream network. The paper concludes with suggestions for further research on both on-site and watershed scales.
Foltz, Randy B. 2003. Environmental impacts of forest roads: An overview of the state of the knowledge. In: Wide, M. I.; Baryd, B., eds. Proceedings of the Second Forest Engineering Conference. May 12-15. Vaxjo, Sweden. Skogforsk Uppsala, Sweden. p. 121-128.