Toward a Low-Cost Structures Design Manual for Rural Roads in Developing Countries

Numerous road construction projects in developing countries have aimed to provide low-cost roads. A major component of these road networks is the structures required to cross streams and rivers. On these projects little attention has been paid to the use of local resources and indigenous skills such as masonry, brick, or manufactured blocks for the construction of highway structures instead of reinforced concrete. A wealth of information is available to designers of highway structures in high-income countries, primarily on the design of large steel and reinforced concrete structures. However, these design guides and textbooks do not address the design of simple water crossings such as drifts, vented fords, or small bridges. There is a clear need for a design manual that provides information and guidelines for highway engineers who are designing structures on low-cost roads in developing countries with limited resources. The findings of desk and field studies for the preparation of a manual for road engineers, technicians, and supervisors in developing countries are discussed. The problems typically encountered in the design, construction, and subsequent use of highway structures are highlighted, and how the manual addresses these problems is discussed.