Various agencies have adopted deterministic models to evaluate short-range and long-range maintenance and rehabilitation planning programs. For problems at network level, these models are expressed in terms of only a single pavement condition index (PCI), or present serviceability index (PSI). Unfortunately, a pavement state cannot be evaluated by a single parameter; thus, the use of a single parameter may lead occasionally to misleading results at the output stage of the planning program. Family models that take into account other pavement-state parameters are therefore needed. It is suggested that the PCI rating method be used together with three additional parameters, which are inserted in formulated models. These parameters are needed for governing the deterioration rate over time (or as a result of traffic); the structural rehabilitation solutions for various pavements at a given PCI value; and the ride-comfort properties of various pavements at a given PCI value. Various tentative values as gathered on the basis of airfield pavements are suggested. Naturally, these values should be considered as no more than preliminary ones, requiring more specific correlation work to specific site observations. It is, however, highly recommended that these values be used at least for conducting sensitivity analyses on the various outputs derived from any pavement management calculations.
Abstract