In this paper a nonlinear deterministic flexible pavement performance model is presented. The model uses the maintenance control index calculated from in-service condition survey data as its independent variable, and pavement characteristics of initial condition, structure and traffic loading as its dependent or explanatory variables. The parameters of the model are estimated using Kanagawa Prefecture Road Network condition survey data. The results of the model show that the model reproduces correctly the actual in-service pavement deterioration trend. This model is simple in its expression, uses a simple estimation method, and uses readily available data, consequently reducing the cost of model estimation. It therefore, suggests a promising avenue for improving the pavement performance prediction and consequently the pavement management system.