400-LB/HP TRUCK ON GRADES: NUMERICAL APPROACH

A set of equations has been developed which successfully approximates the information for 400 lB/h(240 kg/kW) trucks contained in graphs in the AASHTO Policy on Geometric Design of Rural Highways (1965). The equations make possible the computerized generation of a speed profile along a given grade line and could be used in assessing the effects of a variety of traffic patterns on highway capacity and level of service. Problems such as route comparisons, the effect of grade line variations and location of crawler lanes can be treated conveniently.