Author: Salifu Nanga, (M.Phil. MSc. BSc.)
Department of Statistics, School of Graduate Studies,
University of Ghana,
The mortality and morbidity trends from road accidents are rising annually in almost all the developed countries. The total number of deaths and injuries continues to rise despite the decrease in road casualties in relation to the total number of vehicles. Road traffic accident in Ghana is also increasing at an alarming rate and has raised major concerns. In this study, univariate time series was used to model road accidents. The Box – Jenkins method was applied for a 20 year period from 1991-2010.A model was subsequently developed to fit the time series data. SARIMA (1,1,0) × (0,1,1)12 was found to be the best model for road accident cases with a maximum log likelihood value of 245.48, and least AIC value of 5.892, RMSE value of 17.930 and MAPE value value of 1.688. An ARCH-LM test and Ljung-Box test on the residuals of the models revealed that they are free from heteroscedasticity and serial correlation respectively.
Keywords: ARIMA model, SARIMA model, Bank of Ghana, Box Jenkins, Forecasting, Road Accidents