Addis Ababa University Libraries Electronic Thesis and Dissertations: AAU-ETD! >
Institute of Technology >
Thesis - Civil Engineering >

Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/1445

Authors: Getu Segni
Advisors: Dr (Ing) Girma Berhanu
Copyright: 2007
Date Added: 16-Oct-2008
Publisher: Addis Ababa University
Abstract: ABSTRACT Road traffic accidents occur as a result of several factors associated with the traffic system, namely: road users, road environment and vehicles. In year 2004/5, 93% of all accidents involved human factors, 5% accounted for vehicle factors, and 2% were associated with road environments according to the Federal police report. Despite having low road network density and vehicle ownership, Ethiopia has a relatively high accident records. In this regards, the traffic accident death rate per ten thousand motor vehicles in 2001/02-2004/5 was in the range of 129 and 145. Road accidents are concentrated in few of the regions in the country. The capital city of Addis Ababa and Oromia region account for 58 per cent of all fatal accidents and two thirds of all injuries. This study is carried out to identify black spots and possible causes of road traffic accidents and to identify low cost engineering countermeasures. The research is done by reviewing road traffic growth, the existing legislative framework of road transport, and road traffic accidents for the last four years in the country. Previous studies were also reviewed having access to the information in other countries in order to understand the existing knowledge and experiences. Road and traffic data were collected from fieldwork and accident data were gathered from pertinent police stations. Each accident spots was measured with reference to kilo meter post that is available in the Addis Ababa-Shashemene road. A total of 1108 reported accidents were collected out of which 309 were fatal accidents, 206 were serious injuries, and 86 were slight injuries and 507 were property damages. Statistical analysis was made on the collected accident data. The characteristics of accident in built-up (towns) and non built up (rural) areas were tabulated and analyzed separately. Fortysix per cent of the accidents occurred in built-up areas, which covered only 17.7 percent of the study road length. Pedestrian accidents and multiple-vehicle accidents were dominated in urban areas. Single vehicle non-pedestrian and rollover accidents were higher in non-built-up areas. Fifty-two percent of the accidents occurred at tangent and level section of the roads. This is associated with speed limit violation. The results of the study indicated that increases in accident rates were highly associated with gradient and sharp curves. ADT, numbers of lanes and grade have positive relationships with accident rates i.e. the section with less traffic, lanes and grades resulted in less accident rates whenever these variables increased. Similarly, accidents were plotted using GIS software and nine accident black spots were identified. Out of these, six were on scheme roads and three were at intersections. Greater or equal to ninety percentile of accident rate for schemes and junctions were applied in order to select these dangerous sections. At ninety percentile, rate of accident was 3.459 Mvkm for scheme. Six road sections were found above either of the two accident rates. In case of junctions, ninety percentile was 0.728626 Mv junctions. Three spots had above the ninth percentile value and considered for in-depth study. The main causes of accidents at black spots were identified to be unavailability of proper pedestrian facilities, high volume of pedestrian traffic, drivers’ fatigue, lack of awareness of traffic rules and regulations, and violation of speed limit. In addition, densities of accidents per kilometer were verified as a function of access points in towns. Narrow bridges, inadequate sight distances at curves, road curvature, no proper traffic signs, and faded road markings are usually causes of accidents. Finally, low cost engineering measures are recommended to reduce the number of road accidents at identified black spots and other sections. However, the effect should be evaluated after some period.
URI: http://hdl.handle.net/123456789/1445
Appears in:Thesis - Civil Engineering

Files in This Item:

File Description SizeFormat
Microsoft Word - final.pdf3.47 MBAdobe PDFView/Open

Items in the AAUL Digital Library are protected by copyright, with all rights reserved, unless otherwise indicated.


  Last updated: May 2010. Copyright © Addis Ababa University Libraries - Feedback