Economic Decision Model for Low-Volume Roads

Presented is the low-volume roads economic decision model (RED), developed to improve the decision-making process for the development and maintenance of low-volume roads of key importance in Africa. The model performs an economic evaluation of road investment options by using the consumer surplus approach. It is customized to the characteristics of low-volume roads such as the high uncertainty of assessment of model inputs, particularly traffic and the condition of unpaved roads, the importance of travel times for model validation, and the need for a comprehensive analysis of generated traffic, and to clearly define all accrued benefits. RED computes benefits for normal, generated, and diverted traffic and takes into account changes in road length, condition, geometry, type, accidents, and days per year when the passage of vehicles is further disrupted by a highly deteriorated road condition. Users can add other benefits to the analysis, such as nonmotorized traffic, social services, and environmental effects, if computed separately. The model is presented on a series of Excel 5.0 workbooks that collect all user inputs, present the results efficiently, and perform sensitivity, switching values, and stochastic risk analyses. The model soon will be subject to empirical testing using data from selected countries.