Improvement of rural access roads in developing countries with initiative for self-reliance of communities

This study presents an approach to help alleviate poverty from a geotechnical engineering viewpoint. In order to improve accessibility of rural access roads to communities in rural areas of developing countries, a method to reinforce the base course with “do-nou”, a Japanese term for soil bag, has been developed. With this method, local available resources can be mobilized and the community can be involved. The main challenges are to build the base course without the necessity for qualified base course material or compaction equipment to bear the traffic load. The applicability of the available bags in developing countries to the base course was confirmed through tensile strength tests. The effectiveness of the reinforcement of “do-nou” was evaluated through a series of full-size model driving tests. The base course, built with “do-nou” and compacted manually, was able to reduce the settlement of the surface to 33% of that built with the conventional method, just by the spreading of gravel subjected to the traffic load. The technical transfer of reinforcement with “do-nou” to communities in developing countries will make it possible for the members of the communities themselves to work on rural access roads to improve trafficability. The applicability and limitations of road repair with “do-nou” were confirmed through a review of demonstrations and practices in Kenya. Typical sections with flat terrain, sags and gentle slopes, where trafficability was lost during the rainy seasons, were found to be effectively repairable with “do-nou”. Sections with steep slopes, however, are beyond the scope of “do-nou”. From an assessment of the impact after the technical transfer in Kenya, it was found that the application of “do-nou” motivates and empowers the community to initiate its own development. This earth reinforcement technology can be applied to the skills utilized by the communities in developing countries to improve the trafficability of rural access roads by considering the conditions of rural areas. Based on this technology, an approach is proposed to promote the concept of community involvement in repairing rural access roads and to enable the members of communities to improve the conditions of the roads by themselves at a low cost.