| The cost of maintenance and repair of the street network in the District of Columbia (District) is a major financial expenditure. In the District, pavement management is the responsibility of the Infrastructure Project Management Administration (IPMA) which is one of several administrations in the District Department of Transportation (DDOT). IPMA is charged with the responsibility of highway pavement rehabilitation and prioritizing projects on the basis of a process that utilizes pavement condition assessment data. IPMA conducts pavement condition surveys for obtaining the data for determining the functional characteristics of the pavements, more specifically pavement condition index (PCI). During a pavement survey, sections of the pavement are usually observed and rated based on an index of 0-100. A rating of 100 is an indication that the pavement is in excellent condition and the rating of 0 indicates the worst pavement condition.;Over the years, several attempts have been made by many researchers to develop an improved understanding of the performance of pavements, with the aim of formulating model that would subsequently be used to predict when repairs are warranted and what types of repairs are appropriate. Currently, the District uses a Multi-Year Prioritization technique, based on current or predicted conditions, to select treatment and schedule of road maintenance repair, to estimate the costs associated with the treatment and for conducting statistical analyses to match prioritization with budgetary constraints. Prioritization and/or optimization is often based on technique where, several feasible treatments and their effectiveness are examined. Pavement deterioration models are critical for determining the extent of maintenance, repair, and rehabilitation needed and consequently the budget for pavement improvement programs.;The IPMA employs a pavement management system that analyzes pavement improvement needs and develops the budget for pavement improvement programs. The current system used by IPMA involves models that consider pavement treatment rules, treatment cost estimation, deterioration, and a funding option. According to IPMA officials the deterioration model is not adequately reliable. The deterioration models were developed using 'default values' based on dated information that is over 20 years old. The survey methods used for collecting pavement information were vulnerable to severe human error and inconsistencies based on subjectivity. The District now employs modern sophisticated technology for pavement surveys. As a result of the improvement in the quality of pavement survey data, an improved pavement deterioration prediction model could be formulated with much more confidence in its prediction. This research explores the use of the data from modern pavement survey system of IPMA in developing a new deterioration model.;The results obtained from this research revealed that the PCI equation that is derived from the available data is strong and reliable. It can be concluded from the results of the statistical analyses that the sub-grade condition of the pavement affects the overall deterioration of the pavement. Traffic loading appeared not to affect the pavements significantly but based on literature from other studies, traffic loading does affect pavement deterioration. The unreliable outcome from this study could be attributed to having a small sample size and errors associated with the data collection. In addition, apart from traffic loading, time and sub-grade condition, there are other variables that affect the deterioration of pavements. This conclusion is true since all the variance was not explained in considering the aforementioned three variables. |
