Road and Transportation Engineering

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Activity-Based Travel Demand Modeling for Addis Ababa
(Addis Ababa University, 2017-11) Mahlet, Demere; Bikila, Teklu (PhD)
Transportation planning has been shifting from an emphasis on capacity expansion to issues like travel management, social equity and environmental justice, quality of life, energy sustainability, and environmental concerns. The trip-based models are not adequate for reflecting these subjects even if they have served the planning needs of metropolitan areas for many years. The activity-based models, on the other hand, are capable of providing estimates of travel demand under a wide range of scenarios at a disaggregate level. Addis Ababa is currently experiencing high urbanization rates. If this issue is not addressed properly, traffic delays and congestion caused by urbanization will have huge impacts on the environment due to noise and air pollutions. Studying the travel behavior of the residents of Addis Ababa is vital in trying to address the adverse effects of urbanization. In this research, the travel behavior and travel pattern of Bole Sub-City residents were studied. For the purpose of building up an activity-based travel demand model, a discrete choice model was used. Activity diaries were distributed throughout the study area and the respondents were required to fill in their activiites for a period of two days. The results of the survey were then analyzed so as to build up the travel demand model. Daily activity pattern, time-of-day choice, and mode choice models were developed. These three models were linked with each other using a sequential Nested Logit framework. The result from the analysis showed that the daily activity pattern of work tours was accurately predicted by the model, with a goodness of fit of 0.883, as opposed to non-work tours which had a goodness of fit of 0.436. The relatively low goodness of fit value for non-work trips was attributed to the fact that over half of the surveyed population performed work activities leaving the rest of the percentage share to be distributed among school, maintenance, discretionary, and other types of tours. This research can be used as a stepping stone for planners and engineers to further develop travel demand models for other sub-cities found in Addis Ababa.
Addis Ababa Road Traffic Accident Study and Possible Engineering Solutions: Case Study of Akaki-Kaliti Sub City Roads
(Addis Ababa University, 2014-05) Gebremeskel, Atsbeha; Teklu, Bikila (PhD)
This study aimed at examining the road traffic accident and possible engineering solutions: with particular focus on Akaki-Kaliti Sub-City roads. To meet the objective of the research the researcher has given attention to collect accident data, road data, and traffic data from Addis Ababa Police Commission, Akaki-Kaliti Sub-City Traffic Office, ERA (Ethiopian Roads Authority), from Addis Ababa Road and Transport Office, and field observations. Calculation and model selection of Black spot identification go with the land characteristics, objective needs, and basing other real factors required consideration the area of the study. Hence, the results of the study showed the existence of large difference in road traffic accident victims among drivers, passengers, and pedestrian in their sex and age levels. The Male drivers, passengers, and pedestrians were the most affected one as compared to their female counterparts. Moreover, the result confirmed that road traffic accident (death, serious injuries and light injuries) in the city mostly affected age categories of between 18-30 regardless of their sex, and starts declining after age 31. Consequently, the road traffic accidents were extremely affecting the economically active citizens i.e., youths and young adult groups. The road traffic accident trends in the Akaki Kaliti Sub-City roads by day of a week revealed significant growth of the severity of the accidents from 2010/11 to 2012/13 in all days of the week except in Sunday. Though it varies in hours of a day, and hence the crash has reached its maximum points when pedestrians, passengers and drivers' frequency of movement has increased, especially after 6:00 AM and reached the maximum accidents at 10:00 AM. Most of these crushes happened in Central Business District (CBD) and market land use areas with collisions like sideswipe, rear end, collision with pedestrians,broad side, and head on collusion. Most of these accidents occurred on Road junction like midblock than the Y– junction and T – junctions. Besides, the highest accident rates were associated with double carriageway in straight and level road character. Depending on these road traffic accidents and the model used areas like Saris Abo roundabout, Tirunesh Beijing Hospital (Near the Bridge), Customs Office Entrance, Total (Kaliti Shoa Bakery), Korki (Medroc) Entrance, Cheralia Biscuit Factory, and Akaki Kela (Near UNISA) were identified as Black spot areas, since they experienced the highest accident rates. Hence, recommendations of Engineering, Enforcement, Encouragement, and Education like, adequate provision of Road safety education, offering of definite land use policy, Quality drivers' training, and testing, standardized and prerequisite criteria for drives with regard to their educational background and good behavior ,traffic signals , traffic lights and their frequent technical failure should be solved, raised zebra crossing, marking zebra crossing, prohibit overtaking, constructing side walkway, widening of the pavement, streetlights, installation of marking and signs, and some areas also consider adequate median road marking, redesign and providing additional-way movement have been forwarded to alleviate the problems.
An Investigation of The Impact of Sidewalk Vendors on Pedestrian Safety and Pedestrian Utilization of The Sidewalk: A Case Study in Yeka Sub City, Ethiopia
(Addis Ababa University, 2024-03) Abel Seifu; Getu Segni (PhD)
Ethiopia's can benefit from effective NMT, particularly walking. The city's rapid population growth and migration have led to street vending activities, causing obstructions and pedestrian safety threats. This negatively impacts the city's economy, reducing pedestrian service and increasing delays (Sahani et al. 2017; Bahiru, 2019). Traffic accidents cause 1.19 million deaths annually in the world, with pedestrians, cyclists, and motorcyclists being the most vulnerable (50%). Low- and middle-income countries account for 92% of fatalities, despite having 60% of the world's vehicles (WHO, 2023). Ethiopia's road traffic deaths increased by over doubled between 2007 and 2018 (from 2,161 to 4,597), with Addis Ababa experiencing high pedestrian fatalities (Priti Gautam et al. 2020). The study investigates the impact of sidewalk vendors on pedestrian safety and Pedestrian Utilization of the Sidewalk in Yeka sub-city of Addis Ababa, Ethiopia. It uses analysis techniques like ordinal logistic regression, Conjoint Analysis, and Pedestrians' Preference Score to understand perceived safety and predict sidewalk usability. Primary data was collected through questionnaires, surveys, and field observations, while secondary data was gathered from various sources, including Addis Ababa city police commission crash data. The study investigates pedestrian safety in Yeka sub-city sidewalks using an ordered logit regression model, issues vendors and examining relevant inputs. It finds that vendor activity negatively affects safety, while sidewalk adequacy indirectly enhances it. Factors like PLOS and surface condition significantly impact perception, with improved walking surfaces and PLOS variables improving safety. Encroachment on roadways also negatively affects safety, with sidewalks limiting walking opportunities. Factors like sidewalk width, age, frequency, purpose, education, walking distance, and time also influence perceived safety. The study uses conjoint analysis to generate part-worth utility and relative importance values for each attribute level in a hypothetical profile then Total Utility Value was determined. It uses pedestrians' preference score to measure evasion using sidewalks. Key sidewalk attributes affecting walkability, such as width, flow rates, obstructions, and sidewalk condition, are identified. The survey shows walkable width is the most important attribute, with 1.5m-2.5m desirable.
Analysis and Design of Struts to Node Connection of Space Truss In Buildings
(Addis Ababa University, 2007-10) Worku, Emebet; Tebedge, Negussie(Prossefor)
Construction of special structures such as space frames and trusses, shells and domes is to provide large spaces with aesthetically pleasing appearance. Such structures are nowadays finding wide applications in our country. This demonstrated that number of clients interested in the space truss technology is increasing by the day. But considering the lack of standards and codes and training for such special structures design and analysis, currently most of such works are done by foreign engineering companies. These special structures are not yet locally manufactured. This study has as the objective to design, analyze and manufacture space truss made of steel, which acts as a network of struts and nodes with emphasis on the nodes. This may serve as a reference for designers and also to identify how and in what way the nodes can be produced by locally available material and manufacturing means. It is hoped that this will make the construction cost for steel space frames lower and the supervision easier due to the use of readily available local manufacturing methods.
Analysis and Evaluation of Urban Road Traffic Noise Pollution in Addis Ababa City
(Addis Ababa University, 2019-06) Tesfaye, Abdissa; Getu, Segni (PhD)
Addis Ababa city like most of the cities of developing countries are, facing serious environmental traffic noise pollution problem, due to the increasing at an alarming rate of motor vehicles, the expansion of the road network, and poor urban planning. This study is directed to examine the status of highway traffic noise level at different landuse areas along different road class moreover, relationship between noise level and traffic flow is developed. In this study, four main categories of the traffic route and land use are established. Traffic noise levels and traffic volume were conducted 9 times at each 41 selected spots on different days of weeks across four various land use areas of the city for 15 minutes with 3 readings per each period of the day time; morning (7AM-10AM), afternoon (11AM-3PM) and evening (4 Pm-7PM). Statistical analysis of daytime traffic noise in the city was carried out and results are presented in terms of average percentage of exceeded noise level: L10, L50 and L90. Main noise descriptors viz. Equivalent continuous noise level (Leq), traffic noise index (TNI), noise pollution level (LNP) and noise climate (NC) are determined and discussed for each spot per road category and land use. Results of this study indicated that the highest range of Leq 77.2 to 80.7 dBA was observed in industrial zone followed by 75.1 dBA-80.1 dBA in commercial zones, 71.7 - 80.0 dBA in sensitive zones, and 70.0 - 79.1 dBA in residential areas. Observed Leq (dBA), at all measurement points exceeds national and international standard limit values by 2.2 to 25.0 dB (A) and 12.2 to 35.0 dBA, respectively. ANOVA test shows that there is a significant difference (P < 0.05) in noise pollution levels and equivalent noise level in established land use areas. Also, result parameters F-test statistics implies there is no significant difference between overall morning, afternoon, evening time traffic noise level in the city as F calculated (0.005) < F critical (3.07). A linear regression analysis performed between the Leq and logarithm of total traffic volume (log Q) produced a coefficient of determination r of 0.851. A multi regression analysis carried out between the Leq and two classes of traffic vehicle types resulted in a correlation coefficient of 0.7502. Results of this study clearly revealed that total traffic volume and number of heavy transport vehicles are the most significant factors of cities traffic noise pollution. Spearman rank correlation coefficients with value of -0.812 again proved that the classification of urban street noise as a meaning of the road hierarchy is an appropriate part of the design of studies of urban noise caused by traﬃc. In order to reduce alarming condition traffic induced noise levels within the city, both technical actions and nontechnical approaches were also presented.
Analysis and Modeling the impact of Road Network Typology on the Macroscopic Fundamental Diagram
(Addis Ababa University, 2024-06) Tilaneh Tesfahun; Yonas Minalu (PhD)
The population and traffic in cities increased consistently due to the increase in urbanization, economic growth, and increased welfare. This trend necessitates changes in city road network structure in order to satisfy the growing travel demand. This research investigates the relationship between road network typology and the macroscopic fundamental diagram (MFD) in Addis Ababa city road network. The macroscopic fundamental diagram (MFD) refers to the relationship between density, flow, and speed at the network level. The macroscopic fundamental diagram is important in the field of transportation and urban planning. By illustrating the relationship between travel speeds, traffic flow rates, and vehicle density in an urban setting, it gives a macro-level understanding of how urban transportation networks work. The objective of the study is to understand how different road network typologies affect the overall traffic flow and the macroscopic fundamental diagram. Sixty-one 2km by 2km road networks extracted from OpenStreetMap were analyzed using simulation of urban mobility (SUMO) with consistent Origin-Destination (OD) data. The study used geographic information system (GIS) software to gather road network typological data (i.e. road network connectivity indexes, network density, primary road proportion, and trafficable area). Whereas, the maximum flow data were extracted from a simulation of urban mobility output. An exponential regression model was developed to assess the impact of network typological factors on the MFD. The regression model yielded significant results, with an adjusted R square value close to one, indicating a strong correlation between network characteristics and macroscopic traffic flow dynamics. Factors such as alpha, degree centrality, primary length proportion, and network density were found to be statistically significant in influencing the aggregated maximum flow. The study aims to provide insights into how road network characteristics influence macroscopic traffic flow dynamics, aiding in the optimization of transportation systems and urban planning strategies. The findings will offer valuable information for urban planners and decision-makers to enhance transportation efficiency and network design in Addis Ababa City. The research highlights the importance of understanding MFD for optimizing transportation systems and suggests a shift towards holistic urban traffic management strategies based on macroscopic variables for sustainable urban development.
Analysis of Impacts of Speed and Traffic Volume at Black spot areas: Case of Addis Ababa city
(AAU, 2016-05) Meron, Befekadu; Bikila, Teklu (PhD)
Road traffic accidents (RTAs) are a major public health concern, resulting in an estimated 1.2 Million deaths and 50 million injuries worldwide in each year (Tibebe B. and Shawndra H., 2005). In the developing world, Road traffic accidents (RTAs) are among the leading cause of death and injury; Ethiopia in particular experiences the highest rate of such accidents. The main aim of the study was to analyze the Impacts of Speed and Traffic volume at Black spot areas in Addis Abeba city. To identify the black spot areas carried out field data observation and identifying major urban road traffic accident black-spots which was a sub city based analysis of evidences from the city of Addis Ababa, Ethiopia and identified the major accident black spots in each sub-city of Addis Ababa separately. For this purpose, secondary data also obtained from Addis Ababa City Traffic police commission employed. Finally, this research presents Traffic Volume, Speed study results, capacity and level of service of the selected black spot areas. Accordingly, KaraKore – W/Mariam and Torhailoch – Bethel have a level of service of B while Total – Zenebework have LOS of A. However, the segments are currently satisfactorily serving. Synthesis of strategies designed to improve urban transportation Safety and efficiency by targeting speeding and traffic volumes as improving pedestrian facilities in urban areas such as those found in Addis Ababa city.
Analysis of Road Traffic Violations in Addis Ababa City (The cause of Arada sub-city)
(Addis Ababa University, 2018-10) Gadisa, Layo; Getu, Segni (PhD)
Road traffic injury death rates are highest in the African region. Violation of traffic rules, which is a human factor, is an important factor behind traffic crashes and many lives could be saved if all drivers complied with the rules and regulations of road. Other than piece of reports from traffic police, very few is known about magnitude, trends and characteristics of traffic offences in Addis Ababa City. In addition, almost no literatures exists on differences in traffic offences by driver and vehicle characteristics in Addis Ababa city. The objective of this research is to characterize and identify most common traffic offences, trends and magnitudes of traffic offences in Arada sub city over 3 years. Further, this study also investigates differences in traffic offences by drivers and vehicle characteristics. Finally, this study finds attitudes of traffic offenders towards unsafe driving behaviors. Methodology-To achieve the objectives of this research two methods were followed. The first method was secondary traffic offence data collection from Arada sub city over (2007E.C2010E.C) and analyzed. The second method was through questionnaires results from 385 traffic offenders at sub city traffic police department who come to take back their driving license and vehicle plate after paying traffic offence fines. Questions containing traffic offender and vehicle characteristics, history on traffic crashes and frequency of traffic offences for selected traffic offence types and attitudes towards unsafe driving behaviors were prepared. These collected data were analyzed by Excel and SPSS; Independent t-test, one-way ANOVA test, Chi-square, Descriptive and frequencies were used. Results-Over all, 154436 traffic offences registered, 95.6% occurred by male. It showed an increase of 8.3% and 13.04% in 2008 E.C and 2009 E.C respectively. But, the rate is decreasing for female averagely by 2.4% and increasing for male averagely by 13.7%. The most common traffic offences were traffic flow obstruction (12.9%), disrespecting prohibiting signs (11.3%), parking of motor vehicles on prohibited areas (8.5%), overloading (8.2%) and using mobile phone while driving (7.8%). Youth groups (18-30 years) are the most traffic offenders than any other age category and drivers older than 50 were the second traffic offenders as compared to licensed driver population in the city. Drivers with license level 4, 5 and license level 6 (with old licensing system) were more involved in traffic offences than others as compared to their corresponding license population in the city. Code 1, 5 and others (T, CD, UN, ET and police) vehicles showed higher involvement in risk factors of road traffic crashes. Further, vehicles coded 1 showed higher involvement in total traffic offences. Results of Chi-square showed that there is an association of driver and vehicle characteristics and crash involvements. Traffic offenders with degree and above education level, 11-15 years of driving experience, low income, code 3, new vehicles with (0-5 service year) and privately owned vehicles showed higher involvement in traffic crashes than others . Results showed that male (p-value=0.002), in-friendship or cohabited (p-value=0.0022), 3-5 years of driving experience (p-value=0.036), taxis (p-value=0.036), medium income (p-value=0.001) traffic offenders showed higher significant score in speeding at 5%. In case of red-light running, traffic offenders of 24-29 years old, (p-value=0.012), private workers, (p-value=0.003), vehicle service year, 6-10 years (p-value=0.001) showed significant higher score. Finally, respondents have negative attitudes towards unsafe driving behaviors but they still don’t completely translate into positive behaviors. Conclusions- It can be concluded that male, 18-30 years, vehicles coded-1 (taxis), coded-3 (commercial vehicles) and coded-5, and drivers with license level-4, license level-5 and license level-6 were highly connected to traffic offences. In addition, young age (24-29years), new vehicles (0-5years), single and private workers, higher education levels (degree and above), experienced drivers, Buses and private cars also showed higher connection with number of traffic offences and crash involvements. More stringent effort and proper interventions should be done towards these groups and the most common traffic
Analysis of Traffic Congestion and its Economic Cost in Addis Ababa A Case Study of Meskel Square to Kality Interchange
(Addis Ababa University, 2017-03) Kefyalew, Tadele; Bikila, Teklu (PhD)
Cities in the world have faced many challenges like traffic congestion, air pollution, noise pollution and accidents. These challenges especially traffic congestion, is however, expected to aggravate in the nearest future. Due to congestion commuters travel time and vehicle operating costs increase with fuel consumption and emission rates increase with pollutants increases. Following its economic development, Addis Abba has faced traffic congestion problems which cause chronic problems to both the road users and non-users. This paper mainly focuses on traffic congestion analysis and its economic cost by addressing traffic congestion causes, effects, patters and especially its economic cost on the North-South corridor of Addis Ababa. In order to analyze traffic congestion, travel time approach was used whereas analysis of level of service analysis was made using SIDRA intersection based on delay. Afterward, traffic cost is calculated considering delay to passenger vehicles which includes operating costs, extra fuel wasted due to congestion, delay to truck vehicles including operating cost, extra fuel wasted due to congestion by truck, business cost and finally environmental cost of traffic congestion. Then finally, measures to mitigate traffic congestion are recommended based on questionnaire and field visit study. Based on the analysis, it was found that total congestion cost including delay, wasted fuel and operating cost of passenger vehicles and truck vehicles at each road segments on average is about Birr 53.2 million per year. In addition, congestion has costs on the environment and results show that when traffic congestion increases fuel consumption and emission of pollutants increase. From the different traffic congestion measures, improving current light rail transit is the most important since by improving the current status of light rail transit, on the average Birr 25.5 million per year cost of congestion is saved and 11,281.20 kg of CO2 emission is reduced per each road segment.
Analysis on Road Safety Inspection using Analytical Hierarchy Process (AHP) Method A case study in Addis Ababa city
(Addis Ababa University, 2017-07) Getahun, Menbere; Teklu, Bikila (PhD)
Road infrastructure safety is a world issue. Many researches have been done to solve road safety problems. There exist two types of internationally recognized engineering approaches to counter road safety problem, the Proactive and the Reactive approach. In the Reactive Approach, safety improvement interventions are taken after many accidents have already occurred. Whereas Proactive Approach encompasses accident prevention and adoption of corrective measures before accidents can take place. The main objective of this research is contributing to the overall effort in preventing accident occurrence proactively. The study uses both qualitative and quantitative methods of analysis. A simple random sampling was used to select the road section for road safety inspection. The analyses of the research mainly use analytical hierarchy process (AHP) method of pair wise comparisons to distinguish the road components that has a significant effect in contributing to the likelihood of road traffic accident by taking the focus group judgments. In addition two levels of AHP were used to select the road sections with good road way facilities. This study considers four major factors which are road geometry; road surface; traffic sign, road marking and lighting and road side environment. It’s found that the pavement surface condition and cross section of the roads are the significant factors in contributing to the accident occurrence. Finally, in conclusion, AHP is suitable for analyzing the qualitative findings of the field result and identification of the significant factors by keeping the consistency of the judgment. Key Words: - Road safety audit, Road safety inspection, Analytical hierarch process, Pairwise comparison.
Analyzing Road Traffic Crash Injury Severity Causing Factors and Remedial Actions on Modjo-Hawassa Road
(Addis Ababa University, 2022-03) Gobe, Wakeyo; Getu, Segni ()PhD
Worldwide, approximately 1.35 million people die each year from traffic crashes. Also Ethiopia share this traffic crash death. Modjo to Hawassa road is in Oromia Regional State one of Ethiopia’s high fatal and other traffic crash injury severity roads. The road inter connects Addis Ababa city with some parts of south eastern Ethiopia. The main objective of this thesis is to analyze effects of drivers’, vehicle and road characteristics on injury severity of crash victims and assessing the remedial actions. The five year traffic crash data was used. Multinomial logistic regression model is used to analyze the dependent and independent variables. Explanatory variables such as drivers not obey traffic rule and regulation, drivers their ages are between 18-30 years, drivers education levels are high school level, vehicle types are small truck such as Isuzu and FSR and medium trucks like Sino trucks, when roadway conditions are damaged, vehicle defects, light conditions are dark night are identified as factors increasing fatal, severe, and slight injury severity of pedestrians, passengers, drivers and cyclists. Explanatory variable factors such as higher drivers driving experience in years, newer vehicles, when drivers’ age increases, when drivers’ education level above high school, when vehicle types are trucks and trailers and light conditions are day light decreased fatal, severe and slight injury severity traffic crash. Drivers of small trucks such as fright Isuzu, FSR and medium trucks like Sino Truck, which do not obey the roadway rule and regulation most of the time engaged in pedestrians’ fatal crashes and crashes with cars results in fatal and severe injury severity of traffic crashes. The unknown drivers and vehicle types (drivers hit and runs) are drivers which hit and run post crashes and they crashes with pedestrians, animal cart drivers and cyclists at the rural area, night, early morning and evening time. The remedial actions are giving the training on road rule, regulations and guidelines for the drivers, regularly doing road maintenance and rehabilitations for damaged roadway, traffic signs, signals, pedestrians crossing painting color. The findings of the study and evaluations of remedial actions significance are compared with the results of developed country scholar’s researches. The details evaluations of the significance of remedial actions, comparing the results model with mixed logit model, ordered logistic models and factoring independent variable are the research gap of this study and it is recommended as future study.
Asessment of Smoke Emissions Generated from Freight Vehicles at Idling Conditions in the City of Addis Ababa
(Addis Ababa University, 2016-06) Birhanu, Mariamawit; Gebresenbet, Girma (Professor)
Vehicles are the major sources of air pollution. In the developing world old aged vehicles are one of the main reasons why vehicles emit pollutant gases to the environment. The poor transport planning and traffic management systems leading to traffic congestion and hence idling, on the other hand, is the other major reason aggravating emission from vehicles. Vehicle related emissions are known to cause stroke, cancers including childhood leukaemia, lower IQ levels in children and adverse reproductive outcomes, low birth weight and premature birth and respiratory diseases (Suglia et al., 2007). The objective of this research was to quantify the smoke emissions from tailpipes of diesel powered freight vehicles when they idle because of congestion & red light traffic stopping in the city of Addis Ababa; and the relation of these emissions with vehicles age. Considering the patterns of freight movements in the city of Addis Ababa, freight vehicles that entered through the Djibouti Mojo corridor during the year 2015 were used for the analysis as 95% of import commodities is through this route. The major freight destinations in the city were identified to asses and analyze the idling situation on the routes from the entry point to the different freight destinations in the city. An empirical model was developed that combined data of Average Annual Daily Traffic of Freight Vehicles, freight destinations of the vehicles, idling times spent by vehicles on the selected freight routes of Addis Ababa and smoke densities of smoke emissions from freight vehicles. For the completion of analysis, two types of field measurements were performed. One was to quantify the idle times on the different routes towards the major freight destinations and another was to simulate actual road traffic idling at a measurement site and measure the smoke produced from sample freight vehicles per idle situations; referred as „stop and go‟ scenarios, by the use of a smoke measuring instrument called opacity meter . It was found that the age of the freight vehicles in the city of Addis Ababa is a major factor for the emission of smoke from tailpipes. Vehicles‟ age was correlated with smoke emission with a high correlation constant of -0.8. Average opacity values of 80%, 73% 21 % and 8% were obtained for the model year groups of 1959-1991, 1991-2000, 2000- iii 2010 and 2010-2014 respectively from which the opacity values for the vehicles of pre 1991 vehicles resulted in much higher values than the standards of the US Environmental Protection Agency i.e. 50 %. The computed average smoke density from the freight vehicles resulted in a value of 7.6 meter -1 which is very much higher than the threshold set by the standard of the European Union (EU VI). The result from the smoke emission due to idling on each of the routes to the freight destination computed by the empirical model was found to have increased with 93% from the calculated value on the empirical model using the threshold set by the standard of the European Union (EU VI). It was concluded that the level of smoke emissions from freight vehicles in the city of Addis Ababa is very high to cause deleterious impacts on the health of the city dwellers and also on the environment. To tackle the problem, old aged vehicles should be banned from import, optimized traffic management systems should be effected, integrated traffic and environmental laws should be formulated and implemented and stringent laws on smoke emissions should also be formulated and executed.
Asphalt Road Pavement Rehabilitation and Maintenance Case Study in Addis Ababa City Roads Authority
(Addis Ababa University, 2016-03) Girmay, Temesgen; Abebe, Dinku (Prof.)
Addis Ababa City Roads Authority representing the Addis Ababa City Administration manages the entire city roads. Currently it is engaged in increasing Addis Ababa city road coverage to reach 25% within 2012 E.C. However, literatures indicate that most of the city roads severely suffering from lack of proper maintenance. Hence, identifying critical problems can be input towards improving road maintenance and rehabilitation activities of the City roads. After detail review of scientific literature and international experience in managing asphalt maintenance, based on pavement evaluation, maintenance and pavement management system questionnaires was developed and interview was conducted. Through interview and questionnaire survey of professionals; the present maintenance and rehabilitation practice of AACRA was assessed. Responses were graded by average index method. In conclusion, the finding of this study implies that Addis Ababa City Roads Authority doesn‟t conduct adequate pavement condition evaluation that can be sound input for recommending maintenance options and the maintenance work is limited to overlay and pouching and performing maintenance without adequately defining the route cause of distress, moreover this study identifies the greatest challenge for road rehabilitation and maintenance in AACRA is the absence of well established pavement management system. The study recommended that AACRA shall asses and apply alternative pavement evaluation and maintenance methods. Moreover, AACRA has to establish pavement management system to manage maintenance activities for better and optimum utilization of resource. Further research is also recommended which includes development of pavement management system and pavement treatment selection alternatives for Addis Ababa City Roads Authority. Key Words: pavement evaluation, pavement maintenance, pavement management
Assessing & Quantifing the Level of Traffic Congestion at Major Intersections in Addis Ababa (A Case for East-West Corridor)
(Addis Ababa University, 2011-09) Taddesse, Wondwossen; Gebresenbet, Girma (Professor)
Traffic Congestion is an ever growing chronic problem in the transportation system soon after the invention and mass production of automobiles. All major cities both in developed and developing countries are facing the problem due to increasing travel demand which follows economic and population growth. Traffic congestion directly affects commuters with an increased travel time, excessive delay in a queue, increased fuel cost, delay for important appointment and job, loss in productive hours; and it indirectly affects the living standard and the environment as well. Hence, traffic congestion cause upon road users and cities to incur a significant amount of money for both economic and social costs. Quantifying the level of the traffic congestion and understanding how much effect and cost are being incurred due to traffic congestion; hence, will be important for making improvement decisions and evaluate implemented mitigation measures. Following the economic and population growth in Addis Ababa, traffic congestion problem has emerged and the problem is even growing faster. In this study, the level of the traffic congestion in Addis Ababa city was quantified using travel time approach. The city’s one of the most congested East-West corridor was considered and travel time, traffic volume, and vehicle occupancy data were collected at four midblock and four intersections. Accordingly, the travel rate, the delay rate, total travel delay (Veh-Min and Per-min), buffer index and planning time index were calculated. And also, the average hourly travel rate is correlated with the average hourly traffic accident data and congestion spots and accident black spots were plotted on the GIS map to see the relationship between the traffic accident and traffic congestion. Accordingly, the result showed that on average about 18,000 Veh-min or 38 Veh-day and about 169,000 Per-min or 352-person-day are wasted at each major intersection entry and the city incurs annually about 5-8 Million Birr per intersection only for vehicle and fuel cost. The result also showed that the city’s traffic accident rate correlated with travel rate better than traffic volume and the congestion spots identified from questionnaire data conside with the black spots identified by the national road safety agency.
Assessing Challenges and Opportunities of Non-Motorized Transport In Bahir Dar City
(Addis Ababa University, 2019-03) Getnet, Mequanint; Bikila, Teklu (PhD)
A deeper understanding of the challenges faced by the NMT users, and more importantly the cause of these challenges is more crucial when it boils down to delivering a safe and convenient system for all intervention (Mmanake Maria Mokitimi, Marianne Vanderschuren, 2016). The author tried to assess the challenges and opportunities of non-motorized transport or pedestrians and cyclists in Bahir Dar city. Non-motorized transport has various benefits as a mode of transport. But many current urban transportation planning designs does not take in to account the needs of vulnerable road users like pedestrians, cyclists and other slow moving modes. The objective of this thesis is to examine the existing non-motorized transport (NMT) challenges and opportunities that can be addressed by exploring the effective transportation planning and road design mechanisms. The assessment were under taken by prepared questionnaire for pedestrians and cyclists about the existing facilities or sidewalks, presence of zebra crossing, obstacles on journey and other challenges and opportunities of non-motorized transport. The author were also used the three year traffic accident data from Bahir Dar city traffic police commission to determine causes of traffic accident on pedestrians and passengers, movement of pedestrians on the road and amount of accident occurrence, and injured pedestrians based on age and occupation. The general non-motorized transport infrastructure rate by the respondents were grouped under satisfactory and poor. According to Bahir Dar city traffic police data 80.2% of traffic accidents were caused by over speeding, not giving priority for pedestrians and other vehicles and not drive by giving enough headway. Frequent pedestrian movements that cause pedestrian accident were 46.8% at pedestrian crossing point or crossing the road with and without zebra mark. The level of service of pedestrians and cyclists on selected route segments were also determined as LOS C and D. The pedestrian vehicle conflict study result shows that more conflicts were found at intersection crossing due to mainly drivers not priority for pedestrians and sever conflicts were found at mid segment due to over speeding and more parked vehicles on the road.
Assessing Consistency of PCE Values on HCM 2010 For Selected Multilane Highways of Addis Ababa, Ethiopia
(Addis Ababa University, 2023-10) Eaden Haile
Passenger Car Equivalents (PCE) plays a crucial role in road design and traffic management by converting the impact of various vehicle categories on a traffic stream into a standardized equivalent passenger car. Their utilization is essential in a heterogeneous vehicle composition in road traffic. Hence, main objective of this research is to assess the consistency of PCE values in the Highway Capacity Manual (HCM, 2010) for local multilane highways. To achieve the stated objective, three key parameters were considered. Firstly, the assumptions made in HCM 2010 were comprehensively reviewed and compared with the actual local conditions. Secondly, existing relevant literature was surveyed to gather insights from other similar studies. Lastly, data was collected from the Outer Ring Road, a selected multilane highway in Addis Ababa and local PCE values were determined using the flow rate and density method, the speed area method, and simulation with Planung Transport Verkehr AG Verkehr In Städten – Simulations Modell version 9 (PTV VISSIM).The analysis revealed that the direct use of PCE values presented in HCM 2010 is inconsistent with the local conditions. Consequently, the study proposes different PCE values for various vehicle categories and heavy vehicles in general, taking into account the road's percent grade and the proportion of heavy vehicles in the traffic stream. The findings show that, proposed PCE values significantly deviate from those in HCM 2010 due to the variations observed in the local condition. In conclusion, this study underscores the inconsistency of directly applying PCE values from HCM 2010 in road design and traffic management projects. Accordingly, using small values of PCE leads to underestimating traffic volume, underestimating traffic impact, designing inefficient road pavements, and inaccurately analyzing and estimating costs. Hence, the studyadvocates for the use of local PCE values derived from researches which consider the specific local conditions.
Assessing Effect of Speed Hump on Traffic Flow in Addis Ababa at Selected Segments
(Addis Ababa University, 2022-06) Mershaye, Wuletaw; Bikila, Teklu (PhD)
In Addis Ababa the speed calming devices are installed on all road hierarchies with a posted speed limit of 30km/hr for LS, CS&SAS and RR 50km/hr. respectively. Due to the lack of clear and uniform design standards and guidelines for the installation of speed humps in Addis Ababa led to their existence on streets with heavy traffic volumes, which caused considerable traffic delay at the locations of speed humps. The speed hump geometry (Length & width), grade of road along speed hump, speed of vehicles, delay and counted vehicle are used for analysis to generate a regression model. The research has been worked with qualitative(questionary) and Quantitative (direct study) which try to associate the two approaches. In this thesis work, the hump geometry characteristics, geometry of the road, speed of each individual travelling vehicles and delay of vehicles are the main parameters that studied. As per the analysis model the geometry of speed hump has variable effects on vehicle movement at upstream approaching distance of the vehicles. Up to 25-meter upstream distance is used which a car locates at the spot speed of cars approaching the humps with free flow speed taken as first point that 25m before speed hump and can catch up to enough vehicle. The overall result shows that the average maximum speed reduction of 16.66km/hr,15.2km/hr,13.8 km/hr,11.31km/hr. &9.67 km/hr. for (Car), (Bajaj, cycle & motor cycle), (Pick up, Mini bus Taxi), (Medium Bus Truck) and (Large Bus & TT) respectively. From the delay analysis, the car group has maximum delay value (164.5 Veh. /min) than other vehicle groups. In the model, the speed hump height, length and grade of the road has direct relation with the delay at upstream of the speed hump.
Assessing Ethiopian Roads Authority’s (ERA’s) Pavement Management System
(Addis Ababa University, 2016-04) Ali, Kalid; Simeneh, Asres (Mr)
Pavement management systems can assist the engineers in identifying the most appropriate treatment on selected sections of the road network through the use of economic analysis, predictive models and time-series information. The objective of this case study was to review the Pavement Management System’s PMS of Ethiopian Roads Authority (ERA). To meet the above mentioned objective interview and reviewing of archival data at ERA head office were conducted. From the interview and archival data, it can be concluded that Ethiopian Roads Authority was not utilizing its Pavement Management System in full capacity in order to be beneficiary from the system due to different reasons such as luck of sufficient trained staff, breakdown of data collection equipments and lack of its maintenance. Key Words: ERA Pavement Management System,
Assessing Freight Transport Performances in Relation to Delays in Ethiopia: the case of Addis Ababa-Djibouti Corridor
(Addis Ababa University, 2017-06) Waktole, Kalkidan; Gebresenbet, Girma (Professor)
The major contributing factor for low level of logistic performance in Ethiopia is freight transport delay. Delay affects trade performance of a country in terms of cost, time, reliability, predictability and customer services. This study is designed to estimating the actual time it takes for freight to be transported and delivered to the customers, identify the major factors affecting the logistics service quality in terms of delay, identify the constraints that the delay of freight transports has caused to the country, customer, and service provider and finally to develop recommendations based on the analysis made to improve the delivery system by minimizing delays. In order to produce results which are directed to answer the stated problems and meeting the objectives, both secondary and primary data were collected. In relation to secondary data, necessary documents from different public and private organizations were gathered also related documents were reviewed. Regarding primary data, total average time of customer waiting for commodity were measured and questioners were presented to different stakeholders and analyzed using SPSS software. As a result the analysis finds out that on average it takes 37.4 days for transporter companies to transport goods and deliver to customers. The causes of delay are factors related to Djibouti port management problems, Poor condition of Djibouti-Addis Ababa road, bureaucracy, long clearance time at dry ports and check points, poor information flow and lack of integration between stakeholders. At last, the study identifies the impact of freight delay to different bodies and realizes that delay can affect driving behavior, motivation and performance of truck drivers. Likewise, it can reduce truck transaction, performance of freight transporters and customer service and it can even cause waste of time and extravagancy to the driver, can increases storage cost, market price, can reduce goods quality and even perishable goods can be out of date due to delay. Lastly, the study recommends the improvement of Djibouti port management and shipping service of the port, Djibouti-Addis road, the capacity and integration of logistics service providers such as; transport companies, transit service providers, truckers, brokers and shipping agents, the level of service of warehouses, dry ports, customs authority, and it should be simplified & computerized for the benefit of the country and proper implementation of the truck demurrage proclamation. Key words: Delay, Local Dry port, Djibouti port, Warehouse.
Assessing Socio-Economic impact of Road Traffic Congestion in Addis Ababa City in Case of Megenagna to CMC Michael, Ethiopia, Road Segment.
(Addis Ababa University, 2019-03) Sileshi, Setito; Bikila, Teklu (PhD)
As modernization and consequently the urbanization moves forward, the use of motorized transport to maintain the socio-economic and physical integration of city increases. The rise in automobile ownership although not yet very significant together with the poor condition of the roads and the poorly functioning traffic system have resulted in high level of congestion particularly at peak hours, where by the probability of occurrence of congestion is very high. Traffic congestion has various negative impacts ranging from economic loss to adverse environmental and social impacts ranging from economic loss to adverse environmental and social impacts. Generally, transport in Addis Ababa is chaotic, inefficient, unreliable and dangerous. The study focuses on the socio-economic impact of road traffic congestion in Addis Ababa city in case of Megenagna to CMC Michael road segment. The state of the objective analysis of delay, impact of congestion and the total economic cost of congestion were adapted of the methodology based on primary data collections. Which was collected by questioners distributed in to stake holders and traffic volume and travel time were recorded in the field using video recording and its adapted descriptive statistics and analysis by using Statistical Package for Social Sciences (SPSS). Based on the analysis of the result the mean variance significant at 0.05 (P-value < 0.05) so that, road traffic congestion is the impact of socio-economic activities. The average travel speed of the vehicle during the morning and night time is 10.6 Km/hr. But during mid-day the average travel speed is 22.6 km/hr it increased relative to the peak period and still, it is congested. The total average of the speed of vehicles through the segment is 16.6 km/hr. The total time losses in the year are 3850.59 hrs. The total economic cost of congestion had been analysis based on speed-flow curve procedures. So that, the total economic cost of congestion in ETB 42,897752.15.

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