Design and evaluation of very low-volume rural roads in developing countries

Design and evaluation methodologies for low-volume rural roads have traditionally followed an agricultural focus, with an understanding that improved transport, by lowering transport costs, supports economic development through expanding exports and local incomes. More recently, the role of low-volume roads as a crucial complementary input to other activities has been recognized, especially the delivery of essential health and educational services, exchange of information, and basic social interactions. However, limited analytical work has been done to ensure that these benefits are systematically incorporated in the planning and evaluation of transport projects, and experience suggests that the current emphasis of design and evaluation on agricultural benefits can lead to inappropriate priorities and design standards, inasmuch as these are still typically guided by trading off infrastructure life-cycle costs (construction and maintenance) against motorized user savings (vehicle operating costs) and/or increased net income/value-added. There is a need to be more discerning in the application of existing methodologies, as well as to systematically incorporate the socioeconomic role of rural transport infrastructure (including poverty alleviation) into prioritizing improvements. Key to this analysis is the proposition that appropriate design standards need to balance the transport requirements of core economic and social activities with the impact of geography (geology, topography, and climate) on construction and maintenance costs. By taking into account the broader range of impact on local users, the proposed approach encompasses a wide array of options for providing minimum-cost, reliable infrastructure for both motorized and nonmotorized transport.