This report is one of a series of documents dealing with rural development issues related to the planning of human settlements and of their supporting networks within settlements and in settlement hinterlands. This series is not directly concerned with the promotion of basic economic activities in rural areas, e.g., agricultural production or natural-resource exploitation, but there is naturally a close link between these activities and the secondary and tertiary economic activities which grow up in rural settlements as part of the development process. Rural infrastructure is often planned to serve only sectoral rural-development purposes. One of the objectives of this series of reports is to emphasize that rural infrastructure should be planned in a comprehensive context for which settlement development provides a suitable framework.