Rising of road traffic accidents is an increasing concern in Afar region. The purpose of this thesis is to investigate the major road geometric characteristics contributing to road traffic accidents and possible counters measure: with particular focus on Chifra-MilleSemera-Galaffi road segment. To meet the objective of the research traffic crash data, road data, and traffic data were collected from different organizations and site observation of the researcher. Using accident based black spot identification methods, 451 accident data that occurred within the road segment were analyzed starting 2007 to 2009 E.C. From 451 road traffic accidents, 114 fatal, 73 serious injury, 37 slight injury and 227 property damage only accidents were registered. As per Afar regional police commission reports in this road segment 81% of the traffic accidents are caused by human errors, 9% due to vehicles problem, 5% due to defective road environment and the remaining 5% is due to unidentified causes. And also 30% of total accidents are rollover and 55 percent of road traffic accidents occurred on highly winding section of the road. In order to characterize the populations of accidents, statistical analysis was applied to determine the uniformity of the collected data and data processing and interpretations have prepared using SPSS. Depending on these traffic accidents 13 black spot sections were identified using critical accident rate method. Then, the study identified the geometric characteristics contributing to road crashes for those black spot areas by reviewing available geometrical parameters of the road segment and by conducting subsequent site visits. Accordingly, the results of this study showed the existence of narrow bridges around the approach of sharp horizontal curves, insufficient shoulder width and excessive shoulder drop off, inadequate site distance, defects on pavement layer, improper overtaking and speeding of vehicles are the major contributing factors for road traffic accidents in the selected road segment and statistical analysis was performed to check the level of contribution of these factors. Finally, the study recommended possible engineering counter measures for each black spot sections through the selected road segment.