Statistics clearly demonstrate that run-off-the road crashes contribute to a significantrnpercentage of high-severity crashes. It is therefore important for the highway safety communityrnto identify the characteristics and contributory causes of these types of crashes. This paperrnassesses the trends, causes, and severity of run-off-the road traffic accidents and black spotrnidentification by weight severity index method on rural road of East Wallega Oromia regeionrnEthiopia. Despite efforts made by various stakeholders to reduce the massacre on countryrnroads, road traffic accidents have been a serious health problem issue in the country and thernmost severed accident are caused when vehicle run-off-the road and a vehicle that leaves itsrntravel lane at a non-intersection location and collides with another vehicle or with a fixedrnobject or overturns is considered to be involved in a run-off-road crash. The study used datarnon road traffic accidents for the period 2005-2008 E.C and data were obtained from EastrnWallega Police Commission and the data obtained is totally of 374 out of this about 187 ofrnthem are ROR crashes and data has been analyzed using descriptive statistics or Bayesianrnstatistic equation approach/model for identifying the primary contributing factor associated withrnrun-off-the road crashes (ROR). The most frequently identified contributing factor among thernROR events from the model are excessive speeding/exciding speed limit, fatigue, distraction,rnsleeping of driver and tire blow out and brake are out of control, while wrong side driving, toornfast for condition and loss distance, improper turning, motor problem and strapping are morernrelated with NROR crashes. Further the study describes that the degree of hazardousness of arngiven rural road section/stretch has been directly associated with the availability of riskrnindicating on the road such as surface type, geographic location, volume of vehicle on the roadrnand traffic factors. The study finding shows that human errors mainly drivers' behavior andrnactions are found as the major cause of road traffic accident in Ethiopia. So that to reducernfatalities and injuries on the roads, the paper recommends that road safety policy and lawrnenforcement; capacity building, education, and awareness creation; and cooperation andrnintegration between and/or among all transport stakeholders should be the focus of therngovernment as well as the responsibility of every individual living in the country.