Truck Speed and Time Loss on Grades

In the design of grades it is frequently necessary to ascertain the delay to traffic resulting from the decrease in speed of heavily loaded trucks on adverse grades. On routes involving heavy traffic it is particularly important to determine the effect of speed reduction and time loss incurred by loaded trucks on hill and overpass grades upon the operation of traffic at a constant design speed. Where the time loss is large it may be necessary to use preventive or remedial measures, such as an alternate route in rough terrain, a reduction of the rise in grade at an overpass, or in an extreme case the construction of an additional traffic lane, in order to avoid congestion for the anticipated traffic density.