Hawassa University Institutional Repository
Access scholarly works, research publications, and theses from Hawassa University
0
Publications
0
Theses
0
Communities
1M+
Downloads
Browse Collections
Communities in HU Repository
Select a community to browse its collections.
- Academic and research outputs of the College of Agriculture.
- Academic and research outputs of the College of Business and Economics.
- Academic and research outputs of the College of Education
- Academic and research outputs of the College of Forestry and Natural Resources.
- Academic and research outputs of the College of Law and Governance.
Recent Additions
Recent Submissions
ASSESSMENT OF TRAFFIC CONGESTION AND ITS IMPACT OVER SELECTED ROAD CORRIDOR IN ADDIS ABABA CITY
(Hawassa Inversity, 2019-10-19) DAWIT GETACHEW ERGA
Traffic congestion problem is becoming a common problem in most developing countries of
world. This study was conducted with an objective making assessment of traffic congestion
and its impact over the selected road corridor in Addis Ababa City. Through reconnaissance
survey the corridor from ‘Awutobis Tera’ Bus station to ‘Lamberet Menahereya’ in Addis
Ababa city was identified and for analysis purpose the corridor was divided into three
sections. The study was conducted starting from June up to October, 2019. Both quantitative
and qualitative approach were used. 384 samples were used to conduct questionnaire survey
for traffic congestion cause analysis. Out of this 32.5% of the required sample were drawn
from section A, 27% from section B and the rest 40.5% was from section C. For making
analysis on the performance level of road corridors and economic cost of traffic congestion,
traffic volume, travel time delay, average travel speed and vehicle occupancy data were
collected manually for a period of 12 hours a day at 15 minutes intervals on respective road
corridors and for intersections the data were collected for two hours interval during rush
periods. In addition to traffic condition data, the geometric data were also measured as part
of the study. The analysis on causal factors for traffic congestion was conducted by SPSS
software and analysis on level and economic cost of traffic congestion of the selected road
corridor was conducted by utilizing both SIDRA and Microsoft excel. Based on the result of
analysis multi variable linear regression model, the imbalance between vehicle volume and
road capacity, number of pedestrians that cross and move along the side of the road,
inflexible work schedule, inadequate mass transit service along the corridor and illegal on street vehicle parking were identified as the main causes of traffic congestion over the road
corridor. As the result from SIDRA and Microsoft excel showed that the intersections along
the corridor and the road corridor in section C were operating beyond the standard set by
HCM 2010 which recommends LOS ‘C’ or ‘D’. As per the economic analysis result of the
study showed about 2667.8 person-hours/year and ETB104048.75 /year per individual
traveler are being wasted due to traffic congestion over the study road corridor. Building
vehicle parking apartment, elevated pedestrian crossway and improving performance of
intersections were some of the engineering measures recommended to overcome the traffic
congestion problem of the corridor.
MODELING LEVEL CROSSINGS’ TRAVEL TIME AND DELAY CHARACTERISTICS OF ADDIS ABABA LIGHT RAIL TRANSIT (AA-LRT)
(Hawassa University, 2019-04-17) DARIC TESFAYE
Traffic modeling is simplified representation of a part of traffic reality that provides a better
understanding and interpreting of the complex traffic interactions. The objectives of this study
is modeling level crossings travel time and delay characteristics of Addis Ababa light rail
transit (AA-LRT) using simulation and mathematical models and evaluate the operational
characteristics of the level crossings. In the process of achieving the objectives, the study
investigate about peak period vehicle volumes, compositions, routings, LRV arriving
frequency ,speed and the delays experienced. To meet the objective of this research
intersection geometry data from field and traffic flow data at selected intersections is done by
video recording and manual counting. In addition travel time data using light rail transit and
minibus taxi is collected by traveling using these modes to a statistical number of repetitions.
Suitable data inputs in forms of traffic volume, vehicle composition, vehicle routing, speed,
train headway, travel time and delay at different incidences including level crossings are
prepared. These suitable data inputs are introduced into VISSIM and SPSS analysis soft
wares. Finally, the results were interpreted and the key research findings were presented in
two types; i.e. through VISSIM simulation and SPSS statistical models. At the CMC level
crossing the baseline without LRT scenario the average delay of traffic is 134.62s/veh ,the
actual scenario with 00:05:41 LRV headway the average delay of traffic is 135.2 s/veh the
delay increased by 0.43% and twice arrival frequency scenario the delay is 136.22s/veh with
an increase in delay of 0.76% from the actual conditions. At the Sebategna level crossing the
baseline without LRT scenario the average delay of traffic is 22.31s/veh ,the actual scenario
with 00:06:30 LRV headway the average delay of traffic is 23.53 s/veh the delay increased by
5.47% and twice arrival frequency scenario the delay is 33.11s/veh with an increase in delay
of 40.7% from the actual conditions. Additionally as observed in the mathematical model
equation, the train’s travel time is dependent on running time, delay at grade intersection,
open door close door time, close door start movement time and stop open door time in
descending order. It is concluded that the average additional delays at level crossings
increase from the base scenario and with increasing light rail crossing frequencies. In
addition, delay at the level crossing is the second important variable that contributes for the
variability of train travel time at peak hours.
OPERATIONAL ANALYSIS OF UNSIGNALIZED INTERSECTION AND ROUNDABOUT UNDER MIXED TRAFFIC FLOW CONDITION OF SELECTED INTERSECTIONS IN ADAMA CITY
(Hawassa University, 2020-10-06) DARARA BERHANU KURU
Urban traffic congestion is currently severe in most cities in the world due to economic and
social development. Prevalently, Ethiopia is one of the countries that are in rapid economic
development. This influences the travel pattern of the community from their origin to any
destination. Adama is one of busy transportation center in Ethiopia. The city is situated along
the road that connects Addis Ababa with Dire Dawa. A large number of trucks use this same
route to travel to and from the seaports of Djibouti. A little attention has been paid to junctions
and their capacities. There are a few studies conducted to assess the capacity of junctions in
Adama. The main objective of this study was to evaluate operational performance on both
unsignalized and roundabout junctions which are necessary for transport professional’s and
governors to put tangible information for future traffic growth of Adama city. This thesis
addresses the most important element of operational performance of unsignalized intersections
and roundabouts traffic intersections in Adama City on capacity analysis. The methodology
employed for this study was the quantitative descriptive research design which used
quantitative data and analyzed using SIDRA 8.1 intersection software model. The movements
of the vehicles were observed at three roundabouts and seven unsignalized intersections for a
duration of two hours. The necessary geometric data for the analysis (average entry width,
circulatory road width, number of entry and circulatory lanes, and island diameter), traffic
movement data with vehicle characteristics and pedestrian volume were collected. The capacity
analysis was done based on the gap acceptance method that is adopted by SIDRA 8.1 software
program. Based on analysis results, Derartu Tulu roundabouts and six of selected unsignalized
intersections i.e Mebrathayil,Sartera,Wonji,Tikur Abay and Alem Hotel junctions are currently
serving in poor condition of level of service of F by having v/c ratio >1. Genda Gara and
Medanihalem roundabouts are serving at their best operating condition having level of service
A.The rest two unsignalized intersection Geda and Diamond Cafe have level of service of D
and C respectively. The overall level of service of the unsignalized intersections and roundabouts
are serving at poor level of service. Thus, after carrying out additional detail investigation and
taking into consideration future traffic growth appropriate improvement should be made by
concerned bodies
Land Degradation Dynamics Under Land Use Land Cover and Climate Change Projection Towards the Appraisal of Potential Soil and Water Conservation Practices in the Gidabo Watershed, Ethiopian Rift Valley Lakes Basin
(Hawassa University, 2024-10-11) Rediet Girma Legesse
The intricate relationship between land use, climate dynamics, and land degradation profoundly
impacts the sustainability of ecosystems and human well-being in Ethiopia. This study,
conducted in the Gidabo Watershed (GW) within the Ethiopian Rift Valley Lakes Basin
(ERVLB), aimed to assess the long-term land use land cover (LULC), evaluate regional climate
models (RCMs), assess land degradation indicators, and propose management alternatives. To
address these objectives, multidisciplinary approach integrating, remote sensing, geospatial
analysis, statistical metrics and hydrological modeling were used. The study identified nine
major LULC classes i.e., water body, grass land, forest, agriculture, bare/barren land, built-up,
agroforestry, shrub and marsh land. The watershed experienced significant LULC changes
between 1985 and 2021, predominantly driven by agricultural expansion at the expense of
forest, shrub, and grasslands. Future (2035 and 2050) projections using a hybrid Multi-Layer
Perceptron (MLP) and Cellular Automata-Markov chain (CA-MC) model indicated further
agricultural expansion, accompanied by declines in forest and grasslands. Furthermore, the
study evaluated 11 CORDEX-Africa RCMs and their mean ensemble performance, revealing
varied accuracies in reproducing rainfall and temperature patterns over GW from 1991 to 2005.
The observed climate trends indicated a significant declining rainfall (-13.38 mm/year) and
warming temperatures, with future projections (RCP4.5 and RCP8.5) showing consistent
temperature increases. Additionally, the study investigated the impact of LULC and climate
change on surface runoff and sediment yield using SWAT model. The results revealed notable
increases in surface runoff and sediment yield attributed to LULC changes. Whereas, climate
change alone exhibited a diverse influence, with both increases and decreases in surface runoff
and sediment yield. Similarly, the combined effects of LULC and climate change demonstrated
that certain scenarios led to the increases in surface runoff and sediment yield, while others
reduced these processes. This might be attributed to the offset of runoff and sediment reduction
by climate change. Soil erosion rates were found to be high, particularly most of the southern
and eastern parts of the watershed will generate the highest amount of surface runoff and
sediment yield in to the future. Addressing these concerns, soil/stone bund, terracing, contour
farming, and reforestation practice can significantly reduce the annual sediment yield in the
future. The land degradation neutrality (LDN) assessment from 1985–2003 to 2003–2021
revealed land productivity decline, land cover degradation, SOC loss, and the expansion of land
degradation trajectories by 26%. Overall, the findings provide valuable information for stakeholders.
INFLUENCE OF WATER CONTENT AND DRY DENSITY ON THE SHEAR STRENGTH CHARACTERSTICS OF REMOLDED EXPANSIVE SOILS IN ADDIS ABABA, THE CASE STUDY OF KOYE AREA
(Hawassa University, 2020-03-19) TEMESGEN ASFAW ANTE