Empirical models of deterioration for the management of unpaved roads have been developed. Successive cycles of roughness progression and maintenance bladings are represented as a cyclic process reaching a steady-state pattern. One model predicts the minimum, maximum, and average roughness as functions of traffic volume, road gradientand curvature, physical material properties, rainfall, and the interval between bladings. In a second model, the rate of gravel loss ispredicted from similar variables. Both were estimated from extensive data collected in brazil, and both are compared with data from several other countries in africa and south and north america, showing a good degree of transferability. The models have been incorporated in the hdm-iii model for highway strategy evaluation. This paper appears in transportation research record no. 1291, Fifth internationalconference on low-volume roads, may 19-23, 1991, raleigh, north carolina, volume 2.
Abstract