Costs are determined for the maintenance of unpaved roads using motor graders, tractor/towed graders and tractor/mechanical drags based on field work in Africa. The cost-effectiveness is highlighted of using tractor/towed grader combinations for the maintenance of properly constructed roads which are not badly deteriorated. Typical values of maintenance equipment availability for developing countries are given and the effect that this has on the cost of maintenance is determined. A method is proposed for determining optimum grading frequencies for roads using computerised investment models and this has been included in a recommended management method for recurrent maintenance. A grading frequency chart is developed for use by maintenance engineers in developing countries who do not have access to computer methods. (Author/publisher)
Abstract