This report discusses the underlying principles upon which it is recommended that geometric design standards for rural roads in developing countries should be based. The basic elements of geometric design are listed and an indication is given of their purpose and the objectives normally sought when geometric standards are adopted. The development of geometric design standards from first principles is discussed, with particular reference to existing geometric design policies currently being applied in industrialised countries. Finally, the problem of devising appropriate standards for roads in developing countries is considered. It is concluded that the basic standards of safety and comfort that are appropriate for a particular country are a matter for the national authorities to decide. In setting geometric standards consideration should be given to the costs of vehicle operation as well as to road construction costs. (Author/publisher)
Abstract