Predictive Model for Road Pavement Deterioration Indices

Nigeria has a matured flexible pavement road network owned by the public sector called the Federal Road. The 72km road networks from Ilesha – Akure are providing excellent service to road users for interstate movement. Due to movement of vehicles on the road, bitumen pavements tend to crack at some point of their lives under the combined action of traffic and the environment. These cracks are defects in the pavement surfacing which weaken the pavement and allow water to penetrate and cause potholes on the pavement. The results of a study conducted to facilitate the development of road pavement performance models that are appropriate for Nigeria and other similar developing countries, which could predict the rate of deterioration over their lifespan, have been presented. Comprehensive investigations were carried out on the expressway from the Federal University of Technology (FUTA) North Gate to NNPC Mega Station in Akure, Ondo State – apparently one of the busiest section along the road. The data collected are on traffic characteristics, Structural Number (pavement thickness), potholes and other distress types. Using these data and with the help of stepwise regression analysis, models were developed to predict the road pavement deterioration within the area of study and that could be useful for evaluating the failure susceptibility of the road. The calibrated model has 98.8% and 98.7% as R2 and adjusted R2 respectively. The model also has 8.8% (as average) difference between the predicted and actual rate of deterioration. The model can therefore, be used for planning maintenance programs of flexible pavement roads.