SURVIVAL ANALYSIS OF ACCIDENT RISKS OF CAR DRIVERS IN NORTHERN REGION, GHANA

Abstract

The accident risks of drivers and the factors affecting the risks were analyzed using survival models. The data consisted detailed records of fatal accidents in the years 2007 - 2009, generated by the Motor Traffic and Transport Unit (MTTU) of the Ghana Police Service, Northern region. The data on fatal accidents contained 398 drivers. The objectives of the study included both analysis and explanation of driver accident risk factors and investigation of how survival modeling method can be used in traffic accident analysis. The research questions that were addressed include: can driver involvement in accidents and exposure be examined with survival models? Are age and sex major risk factors? Do vehicle characteristics contribute to accident risk? Does the use of unworn out tyres reduce accident risks? The analysis of the data using the SAS package confirmed that the most significant variables to the risks of accident were driver characteristics (age, driver behaviour, kilometerage driven, speed and use of safety belt), drivers’ state (driving under influence of alcohol) and vehicle characteristics (vehicle age and weight, and condition of tyres). Young and inexperienced on one hand, or old and experience drivers on the other hand, had the highest fatal accident risks. Drivers using worn out tyres had a somewhat greater accident risk than drivers using unworn out tyres, but the difference was not statistically significant. Survival modeling was used to analyze the data, and it was concluded that survival modeling promises to be a useful tool for road safety analysis.