Optimization of Farm-to-Market Road Investment and Maintenance Activities in Selected Developing Countries

Abstract

The objective of the administration of farm-to-market roads in countries such as the Central African Republic, Liberia, and South Sudan is to optimize maintenance activities in relation to improving road safety and minimizing life-cycle costs, including road investment, maintenance, and road user costs. The decision on the selection of the most feasible and affordable road dimensions and characteristics, such as all-weather or weather-dependent accessibility, is based on engineering and economic analysis of costs and benefits related to the level of accessibility and the economic life expectancy of the road network. In selected rural areas of African countries such as the Central African Republic, Liberia, and South Sudan, road improvement is a component of an area development program. Traffic volumes are less than 50 vehicles per day (vpd) on these roads, and the development program includes both (a) an engineering and socioeconomic methodology that examines the relationship between road accessibility and agricultural production and (b) social services to evaluate the costs and benefits of the investments of the whole program. Rural investment is most efficient when the most economic type of roadway and the complementary agricultural investments are jointly optimized. The principal benefits achieved are reduced road user costs and reduction of agricultural spoilage. The paper concludes that, when the annual average daily traffic (AADT) is less than 50 vpd, the engineering-improved road surface is the most feasible solution. When the AADT is more than 50 and less than 300 vpd, the most feasible road surface is gravel, and when the AADT is more than 300, blacktop resurfacing is justified.