Roads, by facilitating movement of people, commodities, services and information, affect society in a multitude of ways. A single road may initiate a rural settlement's transition from a subsistence toa trade economy. A road penetrating a previously inaccessible wilderness area may provide opportunities for land development and small industry, but may simultaneously promote massive depletion of valuable natura! ecosystems. Road networks exercise a direct and profound influence on patterns of population clustering and dispersal
