Measures of Short-Term Effectiveness of Highway Pavement Maintenance

Selecting an appropriate measure of short term maintenance effectiveness and determining its value constitute the first in a three-step process for evaluating maintenance effectiveness in the short term. The second and third steps are to determine if the measured values of effectiveness are significant, and expressing such measured values as a function of pavement or treatment attributes. In addressing the first step, this paper investigates and brings into focus various ways in which response variables for maintenance effectiveness models could be formulated with a view to providing a more reliable means of assessing short-term effectiveness of maintenance treatments. For each of three measures of effectiveness, deterioration reduction level, performance jump, and deterioration rate reduction, the paper discusses computational methods and synonymous terms, identifies past studies that have implicitly or explicitly utilized the measure, and discusses associated merits and demerits. Furthermore, the paper argues that the relative timing between pavement maintenance and performance monitoring reported for a given year, is crucial in the computation of any measure, particularly if the interval of monitoring is relatively large. For each of two relative timing scenarios, the paper derives mathematical formula for computation of each measure. Also, relationships between each pair of the three measures are derived for each scenario. Finally, the paper uses field data from Indiana to illustrate the computations and to demonstrate the implications of incorrect relative timing specification on computation of maintenance effectiveness.