DEVELOPMENT OF PERFORMANCE MODELS FOR A TYPICAL FLEXIBLE ROAD PAVEMENT IN NIGERIA

Abstract

The results of a study conducted to facilitate the development of road pavement performance models that are appropriate for Nigeria and similar developing countries and could predict the rate of deterioration over their lifespan have been presented. Comprehensive investigations were carried out on the expressway linking Lagos (the economic nerve centre of Nigeria) with Ibadan (the largest city in West Africa) - apparently one of the most heavily trafficked roads in the country. Data relating to traffic characteristics, pavement condition ratings, distress types, pavement thickness, roughness index, rainfall and temperature, were collected. Models were developed to determine Pavement Condition Score (PCS) and International Roughness Index (IRI). Stepwise Regression was used to analyse the data and quantify the impact of key input parameters on the PCS and IRI. Parameters such as depth of ruts and area of pot holes were found to be statistically significant in predicting PCS while number of patches, length of longitudinal cracks and depth of ruts were statistically significant in predicting IRI. The models can be used for planning road maintenance programs, thus minimizing the need for comprehensive data collection on pavement condition before the maintenance exercise, which is costly and time consuming.