Road and Transportation Engineering
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Item GIS-based cycle Network Planning and Evaluation Of Home to School Trips: A Case of Addis Ababa City, Ethiopia(Addis Ababa University, 2023-11) Zewdu Habte; Yonas Minalu (PhD)A city's quality of life is worsened by increasing usage of motorized transportation and accompanying infrastructure, which results in traffic congestion, environmental pollution, and traffic crashes. To improve mobility on those streets, reduce traffic congestion, improve public health, and make the city more environmentally friendly, non-motorized transport like cycles should have given more attention to the improvement of facilities and the number of cycle users. Engineers and planners in Ethiopia don't, however, have a common procedure for figuring out whether a road is suitable for allowing cycles to operate effectively. As a result, certain circumstances render the transportation system irreversibly unsustainable. In order to improve mobility, a lot of time and effort is put into developing a GIS-based cycle network-planning tool for comparison with the actual state of the planned cycling network. In the example of Addis Ababa city, this study focuses on using a new, highly dependable cycle network design and analysis for home-to-school activities. Utilizing ArcGIS Software which is spatially compatible for network planning activities, the study's methodology was combined with an analysis of the road network utilizing the best route, service area, and closest facility criteria for residents (incidents) and schools (facilities). The data for network development was primarily gathered through site investigation and accounting the ground truth from Google Earth Pro in collecting coordinates of selected Sample of Residence and school locations of the Study area in Addis Ababa city as well as converting to the local coordinate system to fit with the Road network of the Study Area. The study makes use of secondary data, such as the road network from the Addis Ababa City Government Plan and Development Commission (.Shp), as well as reports from various agencies. The closest facility analysis location with the shortest total travel time was RDLocation 7( Shola condominium) -SCL 27(New grand school) where the travel time was 0.309 minutes, and the location with the longest total travel time was RDLocation 4( signal condominium) -SCL27( New grand school), where the travel time was 1.696 minutes. Based on analysis, this study's best facilities network has a total length of 13028.36 m and a total minutes of 202.46. The network service area analysis extension tool used in this study also satisfies the case study area.Finally, the present study evaluates the results from the logical network analysis with the planned cycle network and also with the normal network condition of the road network.Item GIS-based cycle Network Planning and Evaluation Of Home to School Trips: A Case of Addis Ababa City, Ethiopia(Addis Ababa University, 2023-11) Zewdu Habte; Yonas Minalu (PhD)A city's quality of life is worsened by increasing usage of motorized transportation and accompanying infrastructure, which results in traffic congestion, environmental pollution, and traffic crashes. To improve mobility on those streets, reduce traffic congestion, improve public health, and make the city more environmentally friendly, non-motorized transport like cycles should have given more attention to the improvement of facilities and the number of cycle users. Engineers and planners in Ethiopia don't, however, have a common procedure for figuring out whether a road is suitable for allowing cycles to operate effectively. As a result, certain circumstances render the transportation system irreversibly unsustainable. In order to improve mobility, a lot of time and effort is put into developing a GIS-based cycle network-planning tool for comparison with the actual state of the planned cycling network. In the example of Addis Ababa city, this study focuses on using a new, highly dependable cycle network design and analysis for home-to-school activities. Utilizing ArcGIS Software which is spatially compatible for network planning activities, the study's methodology was combined with an analysis of the road network utilizing the best route, service area, and closest facility criteria for residents (incidents) and schools (facilities). The data for network development was primarily gathered through site investigation and accounting the ground truth from Google Earth Pro in collecting coordinates of selected Sample of Residence and school locations of the Study area in Addis Ababa city as well as converting to the local coordinate system to fit with the Road network of the Study Area. The study makes use of secondary data, such as the road network from the Addis Ababa City Government Plan and Development Commission (.Shp), as well as reports from various agencies. The closest facility analysis location with the shortest total travel time was RDLocation 7( Shola condominium) -SCL 27(New grand school) where the travel time was 0.309 minutes, and the location with the longest total travel time was RDLocation 4( signal condominium) -SCL27( New grand school), where the travel time was 1.696 minutes. Based on analysis, this study's best facilities network has a total length of 13028.36 m and a total minutes of 202.46. The network service area analysis extension tool used in this study also satisfies the case study area.Finally, the present study evaluates the results from the logical network analysis with the planned cycle network and also with the normal network condition of the road network.Item Passenger Car Equivalence Under Several Upgrade Road Conditions (For Cases under Addis Ababa City)(Addis Ababa University, 2023-10) Alemzewed Sete; Bikila Teklu (PhD)In developed countries, extensive studies have been conducted to estimate passenger car equivalence (PCE) values under various road geometry, traffic characteristics, and lane width conditions. However, it is important to note that these PCE values may not directly apply to local conditions in Ethiopia since Ethiopia possesses a distinct traffic environment characterized by heterogeneous traffic conditions, diverse road geometries, and unique traffic characteristics. Therefore, relying solely on PCE values derived from studies in developed countries may not accurately reflect the specific conditions and dynamics of Ethiopia's transportation system. There is also a lack of comprehensive understanding regarding the influence of vehicle characteristics in different road configurations in Ethiopia, particularly with respect to PCUs. The Highway Capacity Manual (HCM) of 2010 suggests treating road segments with steep grades separately, given their unique conditions. This study focuses on estimating Passenger Car Unit (PCU) values for six vehicle types, considering variations in traffic volume, road grade, and road lane configurations in Addis Ababa, Ethiopia. Data collection, conducted between 4:00 am-10:00 pm over four hours on Tuesday, Wednesday, and Thursday, covering both one-lane and three-lane roads in four selected areas. The utilization of an Artificial Neural Network (ANN) model aids in training and predicting speed, while the Dynamic PCE method determines PCE values. Multiple regression analysis established a mathematical relationship between PCE, vehicle type, road grade, and vehicle speed using SPSS software. Results indicate varying PCE values for different vehicle types on one-lane and threelane urban roads at different grades. Notably, heavy vehicles exhibit higher PCE on one-lane roads, while buses and medium trucks show consistently higher PCE on three-lane roads. In segments with high road grades, there is an inverse speed impact, starting high and concluding low in three-lane segments, and the inverse relationship continues in one-lane segments, starting with low speed and concluding with high speed on a high uphill grade. Moreover, the obtained PC values surpass those presented in the HCM, signifying their suitability for reflecting the current traffic conditions in the studied locality.Item Evaluation of U-turning Road Traffic crash at Median Opening In Yeka sub city, Addis Ababa(Addis Ababa University, 2023-06) Hailu Amare; Getu Segni (PhD0Road traffic crashes occur as a result of several factors associated with the traffic systems, such as road users, road environment and vehicles. Despite having low road network density and vehicle ownership, Ethiopia has a relatively high number of road traffic accident records. Consequently, Ethiopia is one of the nations across the globe with the highest fatality rate per vehicle. The research was based on the collected data from Traffic Police Office in year between 2017/18 and 2020/21. Field observations were also carried out to collect the required of primary data to be performed as complement to accident analyses. In this research Statistical analysis (multinomial logistic regression analyses) was used to decide the relationship of dependent and independent variables This study tries to analyze the traffic crashes, and develop a preventive strategies and possible counter measures for the route selected as black spot area. The aim is to provide users with an understanding of the major causes of traffic crashes and present using several Statistical tools. In Yeka sub-city the road traffic crash become serious that many people lost their lives, injured and loss of properties. U-turn at median opening traffic crash was one of the most frequently occurring collisions by different causes and area of sub city. Human error, road environment and vehicle factors are main causes of road crashes. In the study area related to driver’s errors were 91 percent, poor weather conditions 6 percent and other factors take about 3 percent. The result of the study showed that higher traffic accident cause by male drivers compared to female drivers. Also the study finds the age groups of 18-30 were mostly affected age of drivers. From the day of the week Tuesday was the highest traffic accident were recorded. And also accidents varies throughout the time of the day, hence times of the day from 7:00am-8:00am, 12:00am-1:00am, and 5:00am-6:00am were the highest accident were recorded. Improper design of cross-sectional elements like narrow Median width, narrow median opening lengths, lack of speed limit and lack sufficient sight distance on the road has been contribute own share for road traffic crashes in sub city.Item Performance Evaluation of AALRT Level Crossings along North- South Line Case study on Adey Ababa and Sebategna Level Crossings(Addis Ababa University, 2023-04) Lemmi Gurmessa; Bikila Teklu (PhD)Railway grade crossings are the intersection of two modes of transportation with very different physical and operational characteristics. There are many variables factors that influence a motorist’s ability to react appropriately at grade crossings. These factors include the information available as the driver approaches, the crossing and human factors such as competing decisions, distractions, and impaired driving. This paper is intended to study the performance evaluation of AALRT Level crossings where road traffic (Road Vehicles), Pedestrians and LRT vehicles (Trains) are computing for crossing each other along the North –south line. This area is one of the important places that belongs to both the rail line and the road as well the bottle neck for the operation of trains. Performance evaluation using Average control delay and Level of service of level crossings were the main topic covered with in the paper. Primary data (Traffic Volume data at crossings) have been collected using Video camera for Six hours at each level crossings. Based on the collected Traffic volume, the traffic distribution to each direction has been counted carefully to minimize the error including pedestrian’s volume. Sidra Intersection 8 software along with Highway capacity manual 2010 (HCM 2010) have been used to evaluate the Performance of theses Level Crossings at 3, 6, 10,15- and 20-minutes’ headway of Addis Ababa Light Rail Transit (AALRT) operation. Intersection models with different Conditions have been considered to see the effects of the presence of pedestrians, Light rail Vehicle (LRV) Frequencies and the type of Traffic Control (Signaling and Yield Sign control). According to the results the presence of pedestrian is sounder in Yield control methods than the Signal control for the same Intersection geometry, LRV frequency and Traffic Flows. Comparison of the Signaling and Yield Control results at the existing traffic condition and Level Crossings geometry conditions shows that Signaling control will perform better than the Yield control. According the result of both from Signaling and Yield control models, both level crossings will not perform at LOS D (Target LOS) at the existing Geometric and Traffic Flow conditions. Finally, the Level crossings were modelled with traffic movement and Geometric modifications under signaling control and the result shows that these level crossings will perform at least at LOS D if the recommended modifications have been set accordingly.Item Evaluating the Major Causes of Road Traffic Accident Occurrence Related to Geometric Design Elements of Addis Ababa -Debre Brehan Trunk Road(Addis Ababa University, 2023-06) Mahder Bekele; Getu Segne (PhD)Road safety issue becomes a worldwide concern specially for developing countries these days since it results in a serious social and economic problems. Several Geometric design and safety research have been undertaken by aiming to improve roadway designs and providing a forgiving roads to the road users. The impact of geometric design factors such as horizontal and vertical curves, lane width, shoulder width, super elevation, median width, curve radius, sight distance, and others on safety has been investigated. However, the relationship between geometric design components and accident rates is remained complicated and unclear since there is a scarcity of data on the association between geometric design features and the accident rates. This study's primary objective is to investigate the geometric design related factors that influence the frequency and severity of traffic accidents on the Addis Ababa–Debrebrehan Trunk Road, by considering design elements such as the average degree of curvature, average gradient, number of lanes, lane widths, shoulder widths and types, median widths and types, total surface width, rural-urban classifications, speed limits, and the presence of structures. As-built drawings, findings from an inventory assessment of the roads, information on traffic volumes, and traffic accidents reports from six consecutive years have been collected for this investigation. Empirical and descriptive statistical analysis models have then been used to analyses the data. In order to analyses the count/discrete outcome variable of traffic accident frequency, a generalized linear model family of Negative Binomial Regression model has been used and Ordinal Logistic Regression Model with Probit link function for severity analysis, by considering geometric design features as continuous and categorical independent variables. As a result, a total of 1192 traffic incidents were recorded and used for evaluation, of which 274 resulted in fatal, 293 in serious injury, 182 in minor injury, and 443 in property damage only crashes. Thus, the model for accident frequency analysis has demonstrated a convergence value for the segment length, average daily traffic, median width, number of lanes, outside shoulder width, average degree of curvature, average gradient, and speed limit. In addition to the frequency model, the severity analysis model has also reached at convergence for the vertical gradient, degree of curvature, availability of structures, median width, surface width, right and left shoulder widths and availability of median barrier.Item Performance Evaluation of Public Transport Service Prioritizing Commuter Preferences for Comfort, Affordability, Safety, and Security: Case of Addis Ababa City(Addis Ababa University, 2023-06) Shambel Assefa; Bikila Teklu (PhD)Public transportation is an essential component of a nation's success, with benefits that extend beyond just those who use trains or buses. To maintain these benefits and continue to attract passengers, it is crucial to evaluate the performance of public transport services. This M.Sc. thesis aims to do just that in the case of Addis Ababa, focusing on five modes of transport, including minibus taxis, midi buses, public service buses, Anbesa buses, and Sheger buses. To undertake this, the study uses both subjective and objective measures, including ANOVA and LOS analysis, tariff comparison, and computation of fatalities and injuries. A multinomial logistic model also employed to determine how commuters prioritized the service aspects of public transport. The results show that minibus taxis were found to be the most comfortable mode of transport followed by public service buses, Sheger buses, Anbesa city buses, and midi buses. The minibus taxi provides the least affordable service, while Anbesa and Sheger buses had the highest affordable service without significant difference. Public service buses, Anbesa buses, and Sheger buses have the highest mean leading safety performance without significant differences. On the other hand, minibus taxis and midi buses are the least performers. Furthermore, the taxi had the highest fatal and injury involvement than other public transport combined. The midi-bus is the least performer interims of security followed by minibus taxi. The model also revealed that monthly income, age, frequently used mode, and education level have significant predictors for commuters’ modal preference decisions. This research contributes to policymakers by providing recommendations for designing transportation policies that better meet the needs and preferences of the public, leading to increased ridership and improved access to transportation for all.Item Evaluating Red-Light Runners at Signalized Intersection in Addis Ababa(Addis Ababa University, 2023-06) Sisay Asrat; Getu Segne (PhD)The conduct of red-light-running is widespread and growing in the world. The problem has been explored in different countries with less attention also in Addis Ababa. This paper examines the relationship between violation frequency and influencing factors related to red light running. The data for the current study has been taken from Addis Ababa traffic police; reported traffic rule violations including red light running behavior in Addis Ababa for four years (2018 to 2021) were analyzed using an Excel spreadsheet. Structured questionnaires were also distributed to the willing drivers with 412 rates of participants and analyzed using a chi-square test to demonstrate the rate and contributing factors to red light running. In addition, four signalized intersections namely Shola Gebeya, Legehar, Churchill, and Semen Hotel were randomly selected. Multiple linear regression analysis has been calibrated to assess the effect of the independent variables on the red-light running violations as the dependent variable by SPSS software. From the statistical analysis made on the collected traffic rule violation data, it can be seen red-light running violation rate is becoming increasing in recent years in the city and it also shows that Bole and Lideta sub-cities have higher rates of violation among the eleventh sub-cities. Gender, age, educational background, and driving experience were found as dominant influencing factors affecting red light running behavior in Addis Ababa. Most drivers were more likely to engage in RLR and would speed up at signalized intersections when they are in a hurry in the morning peak hour on working days they mostly prefer to run the red light to save time. Empirical results exposed that Car, number of lanes, red light time, cross road width and green light time, were found statistically significant at 95% of significance. Green light time, heavy vehicle, and cross road width are negatively related variable with red light running and affects negatively while car, bus, yellow light runners, Pedestrian, number of lanes, grade and red-light time are positively affecting the red light running. Finally, low-cost engineering countermeasures including optimizing the traffic light, education, and awareness campaign are recommended to reduce the number of red-light running conduct at signalized intersections. The education on red light running offenses must be accompanied by frequent Police enforcement of the traffic law to reduce the degree of violation.Item Assessments of the primary factors affecting driving speed and the violation of the speed limit by drivers in Addis Ababa(Addis Ababa University, 2023-06) Tareqwa Tsegaye; Getu SegnE (PhD)Infrastructure projects, such as road construction, are one of the most important projects in Ethiopia. Growth in this sector is critical for growth in national income as it is among the largest sectors that generate employment within the country and is a key driver for the economic development of Ethiopia. Addis Ababa Roads Authority has administered road projects at the city level, and traffic is controlled by Addis Ababa City Administration Traffic Management. Traffic control includes posted speed limits, traffic warning signs, and traffic lights. However, the posted speed limits are not well known by the drivers, and most of the time drivers violate the rule by over speeding. There are several factors that contribute to these posted speed limit violations. In order to reduce speed limit breaches, future work should focus on identifying the main causes of violations of the posted speed limit as well as the main factors influencing drivers' speed when operating a vehicle on Addis Ababa City roadways. A detailed analysis of the literature and desk research was conducted, and the results allowed for the identification of both global and local causes of speeding violations and factors influencing driver speed. This paper focuses mainly on two data sources, which are collected directly from the road (spot speed of vehicles) and closed-ended questionnaires. Spot speed data on different road types and 450 questionnaires were distributed to randomly selected drivers by convenience sampling. Multiple linear regression models for the average speed of vehicles on a section (50th percentile speed). Furthermore, the driver’s compliance with the posted speed limit is analyzed by using ordinal logistic regression through self-reported violations. The likert scales have been analyzed by using cross tabulation and bar charts for causes of speeding as per driver perspective and compliance with the posted speed limit. As a result of the study, the independent variable inputs are statistically significant with a Pvalue of less than 0.05 with a 95% confidence interval, and they have a significant effect on the 50th percentile speed. For ordinal logistic regression through self-reported violations, gender of drivers, marital status of drivers, age of drivers, and driving experience of drivers have a significant effect on the violation of speed with a P-value of less than 0.05 with a 95% confidence interval. On the other hand, drivers have the intention of complying with the speed limit and also understand the effect of speeding. However, they still do not comply with the speed limit. Commercial drivers agree that income affects violating the speed limit, and most commercial drivers understand that complying with the PSL affects their per-day income.Item Characteristics and Effects of On-Street Parking in Addis-Ababa A Case Study on Marked Box Parking Facilities in Nifas Silk Lafto Sub-City(Addis Ababa University, 2023-06) Wengel Yilma; Bikila Teklu (PhD)As of now in Addis Ababa there are so numerous issues which are basically concerned with deficiency of stopping space such as congestion of streets due to imbalance between on-street parking capacity and demand of parking space by vehicle and Regarding this problem Addis Ababa city traffic management agency has been implementing different types of parking facilities one of which is marking of Box on Street parking areas on the outer lane of the existing roads. However; the effects of these areas on existing traffic and efficiencies of these parking facilities on service condition are not assessed adequately. Therefore this study asses accordingly the effects and efficiencies of legal on street parking in Addis Ababa a case study on Nifas silk lafto Sub-City From Bisrate gebriel square to Karl square. methods used for data collection were field survey to conduct a comprehensive parking occupancy survey ultimately to find the characteristics and efficiency of the parking space, to find vehicle maneuvering time which are used to estimate the reduction of the adjacent lane capacity because of disruptions of traffic flow while maneuvering of vehicles from parking lane. In the instance of secondary data collection, relevant information was retrieved from relevant materials, such as published literature and internet-based sources. The results of the study indicate that on-street parking facilities in Bisrate Gebriel square to Karl square road segment are inadequate mainly on mid-day period leading to illegal parking. Another result of the study shows that reduction in lane width of traffic lanes and vehicle maneuvering of parking vehicles on adjacent lane impacts road capacity. The average speed of vehicles by 6.25 %.Which was found to reduce a speed of 0.0382 km/hr. for each percentage increment of parking occupancy when on-street parking is considered removed from the kerb side of the road this reduction on road capacity due to both allocations of traffic lanes for onstreet parking and Disruption of Traffic flow of adjacent lane.Item Safety Performance of Speed Humps with Rumble Strips in Addis Ababa(Addis Ababa University, 2024-01) Tigist Eshetu; Getu Segni (PhD)With increasing urbanization, vehicle density on the roads has been increasing exponentially. Most of the vehicles and roads are designed for a particular speed. The improved roadway facilities have encouraged the drivers to drive fast in the urban roads. Excessive speed is a key risk factor for road accidents and greater severity of the injuries in the event of an accident. In such circumstances, it is very difficult to control a speeding vehicle unless some speed management measures are provided. In our city Addis Ababa speed calming interventions are implementing on the selected road segments of the city. The primary aim of this study is to evaluate the safety performance of speed humps with rumble strips in the context of Addis Ababa. To achieve this objective, two types of data were employed: primary and secondary data. Secondary data was utilized to gain insights into the characteristics of accidents on the specific road segments under study. In contrast, primary data was speed survey data, road segment length data and frequency of speed hump (number of speed hump and rumble strips) for the selected road segments. The speed survey data was thoroughly collected using ERA pavement design manual Volume I, 2013 Vehicle classification table. The Secondary data (accident data) covered the years 2014 to 2021 (2006 to 2013 E.C.) and was sourced from the Addis Ababa Police Commission and various sub-city police departments. The speed survey indicated that 85th percentile speeds were maintained below the speed limits of 30km/h by a considerable percentage at different points along the road segments: 46% 20 m before the speed hump, 92% at the speed hump, and 23% 20 m after the speed hump, across the total selected road segments. The T-test results for Traffic speeds are statistically significant for all variables and for all three pairs except Large Truck on before 20m of speed hump and after 20m of speed hump pair. Following the implementation of speed humps with rumble strips, the study shown a 31% reduction in Total Equivalent Accidents (EANs), a 24% reduction in total pedestrian accidents, a 54% reduction in pedestrian accidents involving crossing on the roadway, a 2% increase in pedestrian accidents involving walking straight and a 35% reduction in accidents involving public transport vehicles.Along with T-test results, it can be concluded that speed hump with rumble strips are effective in reducing accidents. When we can see the impact of speed hump with rumble strips on pedestrian safety the results also shows a significant change in the before-and-after study. With respect to pedestrian accidents by main activity speed hump with rumble strips the result also shows a significant change it can be concluded that speed hump with rumble strips are effective in reducing accidents Pedestrians Crossing on Roadway. This affirms that speed hump with rumble strips help in safe Crossing on Roadway. This means pedestrians can Cross relatively easier and are safer than Crossing on the roadway without speed hump with rumble strips. A T-test carried out on Pedestrians Accident Walking Strait in the before-and-after study indicated no significant change. Using results of this T-test, we can conclude that, speed hump with rumble strips, in this case, do not effect a significant change in reducing Pedestrians crashes Walking Strait. A T-test carried out on public transport study indicated no significant change. Using results of this T-test, we can conclude that, speed hump with rumble strips, in this case, do not effect a significant change in reducing public transport crashes on the road. Regression analysis used to produce the best relationship between density of speed hump and 85th Percentile Crossing speeds of the vehicles. Generally, the simple linear regression model that include one independent variable (85th Percentile Crossing speed) .The signs of the correlation coefficients in the regression model are as expected. The density of speed hump shows a positive correlation with 85th Percentile Crossing speed.Item Impacts of Pavement Surface Condition and Geometric Characteristics on Traffic performance at Mid-Block Road segments (In the case of Addis Ababa City)(Addis Ababa University, 2023-12) Yematawork Tasse; Bikila Teklu (PhD)This study focuses on investigating the influence of pavement condition and geometric characteristics on traffic performance in different segments of Addis Ababa city. The research was conducted on five collectors and one sub-arterial urban street, specifically examining pavement distress, lane width, lane number, walkway width, road gradient, traffic volume and travel speed. The statistical analysis revealed that certain geometric factors, such as lane number and width, remained consistent across the segments and did not significantly affect travel speed. However, walkway width and road gradient exhibited notable variations in different sections. Further analysis indicated that walkway width had a weak correlation with travel speed, as indicated by a p-value exceeding 0.05. Consequently, walkway width was excluded from the multiple regression model, suggesting that it does not have a significant impact on travel speed between Coca-Cola-Mesalemia and Tikelhaimanot to Mexico Square. In this study, the impact of various factors on travel speed in different sections of Addis Ababa city was examined. Variables such as traffic flow, road grade and pavement condition were found to significantly influence travel speed, as indicated by their p-values being less than 0.05. To compare travel speed between distressed and non-distressed sections, travel speed was conducted during off-peak hours, keeping other factors constant (driver behaviour and environmental factors). The results showed a significant reduction in average speed in the distressed sections compared to the non-distressed sections, with reductions ranging from 53.42% to 68.85%. The study suggests that, in addition to rehabilitation, implementing periodic maintenance and ensuring proper geometric design can greatly improve traffic performance in these road segments and the economic analysis shows that distress rating between failed to very poor has more expense than of a distress rating poor to Good.Item Assessing Consistency of PCE Values on HCM 2010 For Selected Multilane Highways of Addis Ababa, Ethiopia(Addis Ababa University, 2023-10) Eaden HailePassenger 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.Item Safety and Security Evaluation of Three-Wheeler Taxis as a Public Transport Mode in Kombolcha City(Addis Ababa University, 2023-11) Abebe Wondimnew; Getu Segni (PhD)In Kombolcha city, three-wheeler motor vehicles (Bajajs) serve as the primary mode of public transportation. Even though these motor vehicles have been designed for the purpose of public transport in developing countries, there is a lack of sufficient studies on their safety and security as a public transport mode. Based on that, this study examined the safety and security status of these three-wheeler taxis as a means of public transportation in Kombolcha city. To do that, questionnaire data from 395 respondents (passengers and drivers) and police-recorded crime as well as crash data were collected and analyzed. From the analysis, it was found that pedestrian collisions, overturning or toppling, and passengers jumping and falling while the vehicle was in motion were the most common types of accidents in 3-wheeler (Bajaj) taxis. In addition, multinomial logistic regression analysis was used to predict the severity level of crashes; in doing so, vehicle type involved in a crash, accident type, and accident causes were the factors that affect injury severity level at a significant level of p = 0.05 and a 95 percent confidence interval. According to the findings, the most common type of injury in 3-wheeler accidents was injury crashes, and pedestrian collisions were found to be the leading cause for the severity levels. On the other hand, three years of crime data indicated that 3-wheeler-related crimes show an increasing trend, and as per the logistic regression analysis result, male passengers were more likely than female passengers to be beaten or hit, whereas female passengers were more likely to be robbed, snatched, or stolen. Additionally, the study indicated that 3-wheeler stations, the vehicle itself, and the way to or from 3-wheeler stations exposed travelers to crime incidents. For instance, theft crimes were higher inside 3-wheelers, whereas robbery/snatching and beating/hitting crimes were more common outside the three-wheelers. In general, passengers' feelings of safety and satisfaction level with security-related services significantly depended on gender, age, travel frequency, and occupation, with female passengers feeling more unsafe and dissatisfied than male travelers. Overall, on Wednesday and Saturday, traffic and criminal activity in Kebele 03 of the city were higher and need close supervision by the city's traffic and regular police, respectively.Item Identifying Integrated Factors Influencing Pedestrian Level of Satisfaction on Existing Pedestrian Facility (In Case of Addis Ababa: - Mexico, Megenagna and Aratkillo Walkway)(Addis Ababa University, 2023-06) Amanuel Zemene; Getu Segnie (PhD)Walking is the best sustainable mode of transport because it is not only cheap but also zeros emission transport system. Walking mode of transport do not require special skills, because they are deemed convenient for all groups, where people manage the intensity of their movements themselves. Despite the advantage of walking mode of transport, there is no standard pedestrian facility not only in quality but also the capacity Therefore, the main objective of this study is performance evaluation of pedestrian level of service and assessing the existing pedestrian walking facility level of service in terms of pedestrian satisfaction level. In order to achieve the objective of this study ordinal logistic regressions have been employed by following factor analysis of multiple external factors in addition to HCM2000 method. A total of 390 pedestrian attitudinal surveys and pedestrian video graphic survey had been taken for the analysis. The method of analysis was logistic regression analysis by following principal component analysis of multiple external factors and HCM 2000 method for performance evaluation of level of service. Based on the result of factor analysis (principal component analysis), four major grouped factors have been extracted such as walking facility problem, traffic safety problem, comfort and convenience issue, and security problem that have been able to explain the total variance of 32.6%,21.3%,13.5% and 8.4% respectively. As per the result of ordinal logistic regression external factors such as walking facility problem, as comfort and convenience, and traffic safety problems are found to affect pedestrians’ level of satisfaction on existing pedestrian facility. From socio-demographic characteristics of pedestrian Education level, Age category, Health condition, and purpose of tripe and income level of pedestrian are the most significant variable which influence the satisfaction level of pedestrian in addition to external factor. The level of service of selected existing pedestrian facility are also found very lowest which are PLOS E, D and F based on different parameters.Item Speed-Flow-Density Relationships for Traffic on Two-Lane Two-Way Rural Highways (The Case of Ethiopia)(Addis Ababa University, 2023-07) Anuwar Mohammed; Bikila Teklu (PhD); Tamiru Tilahun (Mr.) Co-AdvisorUnderstanding the relationship between speed, flow, and density is essential for policymakers, designers, traffic engineers, and other professionals in determining operational capacities, reducing traffic congestion, improving traffic safety, developing effective traffic management strategies, designing highways, and improving overall traffic stream performance. The Highway Capacity Manual, which were developed based on traffic and geometric conditions of the United States of America, were used in Ethiopia to study the Speed-Flow-Density relationship for Two-lane Two-Way Highways, which was necessary for capacity analysis and assessment of the overall operational performance. Moreover, no established travel time-flow and travel time-density relationships were studied, which is needed for transportation planning and traffic demand management purposes. To that end, it is crucial to examine those relationships by calibrating data obtained from those highways in order to obtain a capacity value that better reflects the actual traffic conditions and make conclusions regarding travel time relationships. On three selected two-lane, two-way rural highways, traffic data was collected from both sides of the flow during the peak hour in the morning using video recording. Using an electric pole nearby the road stretch as a reference, travel time data and vehicle classes were recorded. Data processing was done using Adobe Premiere CS6. The average speed was calculated by dividing the measured distance between the reference points to the vehicle travel times averaged for every 1-minute and 15-minute time intervals. The average flow was computed by counting the vehicles passing, converting heavy trucks into equivalent passenger car equivalents, and using the steady state equation density was determined easily. This study employed a regression approach for assessing different classical speed-density models, including Greenshields, Greenberg, Underwood, Drake, May and Schofer (North Western University Model), Drew, Multi-Regime Matrix, and Composite Models. At both 1-minute and 15-minute time intervals, the analysis revealed that the multi-regime matrix model better explained the data than the other models. With this model, the steady state equation was used to establish the corresponding speed-flow and flow-density relationships. Finally, based on the developed speed-flow relationship, the capacity for both time interval analyses were less than the Highway Capacity Manual's recommended maximum capacity value, and the value of capacity obtained using the 15-minute time interval was less than the corresponding 1-minute time interval analysis. Furthermore, the travel time relationships matched the curves obtained with previous studies for similar highway types.Item Investigating Effects of Road Geometry on Accident Blackspot of Addis Ababa to Gohatsion Trunk Road(Addis Ababa University, 2023-06) Berhanu Seyoum; Getu Segne (PhD)Ethiopia is experiencing high number of traffic accident record contrary to the low road network density and least number of vehicle fleet when compared to the world. The increase in occurrence of traffic accident is due to increase in motorization without regulation and rapid population growth and increase in road network density with poor attitude and safety consideration while designing and constructing the roads. Along with expansion of the road network mandatory road safety policy was not developed, clear and updated legislations were not formed and capable institutional organization for implementation were not established to take safety into consideration at early stage of the design of the road. The purpose of this study is to identify the black spots along the road under the study and to investigate the relationship of the geometric design parameters of the road at blackspot locations with road traffic accident when compared to the recommended standard set by ERA. Three years‟ traffic crash data were collected from six woredas (Wacaalee, Debrelibanos, Giraar Jaarsoo, Dagam, Kuyyuu and Warra Jaarsoo) and three town administrations (Fitche, Chancho and Sululta) along Addis Ababa to Gohatsion trunk road and as built data were collected from Ethiopian Roads Administration (Road Asset Management Directorate). Supporting these secondary data with primary data, thirty-seven blackspot locations were identified using Rate Quality Control (Accident Rate, Accident Frequency and Severity Index) method and Accident density method and these 37 blackspot locations are mapped using GIS Software. The geometric design parameters of the road at these black spot locations are further analyzed using SPSS software. Multiple linear regressions were fitted to explain the number of accident based on lane width, shoulder width, supper elevation, vertical curve, gradient, 85th percentile speed and minimum clear zone. Among the explanatory variables supper elevation significantly affects number of traffic accident, whereas others moderately.Item Developing Superpave Bitumen Performance Grade Mapping for Ethiopia: Adapting to Historical and Future Climate Condition(Addis Ababa University, 2023-06) Birhanu Demissie; Robeam Solomon (PhD)The study aims to adapting a Superpave bitumen specification performance grading system for Ethiopia, considering historical and future climate conditions. By conducting statistical analysis and examines the performance characteristics of different bitumen grades across varying temperatures. Historical climate data from 1990 to 2020, obtained from the Ethiopia National Metrology Agency, establish the baseline climate conditions. Future climate projections from 2020 to 2100, based on two global climate models (CMIP6) and climate change scenarios (SSP 2(4.5) and SSP 5(8.5)), are used to assess future conditions and prediction pavement temperature using SHRP and LTPP models. The findings indicate that, for different reliability level, PG58-10 and PG64-10 are predominantly required in historical contexts, yet future projections indicate a notable transition towards PG64-10 and PG70-10, encompassing a larger expanse of the country. Furthermore, the Afar region and western Ethiopia are projected to necessitate PG76-10 in the future. A considerable number of locations in Ethiopia mandate one grade increment due to climate change, exhibiting average percentage increases of 20%, 23%, and 27% for the moderate climate change scenario SSP2 (4.5), and 44%, 27%, and 35% for hottest climate change scenario SSP5 (8.5) of the study area during 2020-2040, 2040-2070, and 2070-2100, respectively. Climate change significantly impacts road pavement performance in Ethiopia, resulting in an overall elevation of grade changes as observed. Specifically, under the SSP5 (8.5) scenario, Adigrat and Sekota locations experience a two-grade increase. Additionally, t-test is employed to compare two pavement temperature prediction models, revealing a statistically significant difference in Superpave bitumen specifications due to the characteristic nature of the models. However, both models demonstrate effectiveness in predicting pavement performance grade (PG) and evaluate performance of currently used asphalt grade using DSR-machine with the SHRP PG determination criteria of penetration-grade fail temperature for pet-grade 40/50(69.29oc unaged and 71.66 oc for Aged Sample),60/70((68.03oc unaged and 64.52 oc for Aged Sample),80/100((59.13oc unaged and 59.66 oc for Aged Sample) &85/100(62.35 oc unaged and 61.35 oc )then the recommended PG Grade are PG64,PG64,PG58&PG58 Respectively. Finally, the study proposes a new performance grading system for Ethiopian roads, considering future climate conditions. The findings provide valuable insights for policymakers and road construction companies in EthiopiaItem Evaluation of Construction Demolition Wastes of Buildings in Addis Ababa to be used as a Sub-base Material: Case study Around Mexico Area(Addis Ababa University, 2022-07) Yohanes, Abebe; Robeam, Solomon (PhD)Utilizing recycled materials and wastes like construction wastes and demolition reminders is one of the justifiable solutions in terms of both cost minimizing and environmental concerns of transportation infrastructure constructions. The main objective of this study is to evaluate the suitability of the usage of Construction Demolition wastes of buildings in Addis Ababa to be fully or partially used as sub-base layer. The scarcity and difficulty of providing construction materials like sub-base has been a challenge that drags the road construction and the pavement industry not to be continued as expected. On the other hand, in Addis Ababa the extensive production of construction and demolition waste and lack of disposition areas due to the overpopulation of the city have a great contribution on the environmental pollution and it is also becoming a problem. In this research, Construction Demolition Waste samples were collected from Addis Ababa around Mexico Area. Four samples were collected which are CDW1 (from Previous GomaKuteba compound), CDW2 (from left side of Yobek Building), CDW3 (from the back of Wabishebele Hotel) and CDW4 (in front of Ministry of Health). Gradation, Proctor Compaction, CBR, Atterberg Limits as well as LAA tests were conducted on all of the collected samples. However, all the samples pass the gradation requirement but could not pass the CBR requirement for subase material. Their Maximum Dry Densities (MDDs) are also lower than the expected MDD for subase. Therefore, in order to increase their densities and their bearing strength, it was tried to mix two of the CDWs with Clay material with four proportions (10%, 20%, 30% and 40% by weight of the sample). The MDD and the CBR have shown a big increment when 20% to 30% of Clay material is mixed with both of CDW samples and fulfill the CBR, Liquid Limit and Plasticity index requirements for subase material in accordance to the ERA specification. However, all the CDW samples have higher LAA value than expected for subase material. Therefore, it was required to reduce the LAA value of the samples and it was tried to mix two of the samples with approved subase material with four proportions (10%, 20%, 30% and 40% by weight of the sample). In doing that, both of the samples fulfill all the ERA specification requirements and the LAA requirement as well. In addition, it was tried to simulate the compaction during construction on site by proctor compaction and study the gradation curve after compaction. In order to do that, the samples left from pure CDW1 and CDW1 + 20% Subase were taken and compacted by standard proctor compaction procedure and the gradation of pure CDW1 after compaction tends to cross the upper limit allowable for subase material, whereas the CDW1 + 20% subase sample’s gradation lies in between. Therefore, CDWs + 20% subase pass all the laboratory test requirements in this research for subase material and 20% subase content is recommended as the optimum proportion of subase which is the minimum requirement. However, using more than 20% subase also fulfil all the requirements specified for subase material.Item Evaluation of Sand-Bitumen Mix and Rubber Membrane Joint Sealants for Ongoing Rigid Pavements in Ethiopia: Case of Ditchoto Galafi Concrete Road Project(Addis Ababa University, 2022-06) Sara, Getachew; Robeam, Solomon (PhD)As a part of its Road Sector Development Program (RSDP), the government of Ethiopia has been investing a significant amount of money in constructing different surface type roads. And, due to its higher life span, low maintenance and operation cost, rigid pavements (cement concrete surface types) have been emerging as the preferred pavement type to be constructed in high-temperature areas like the eastern part of Ethiopia, where there are 195.5km long ongoing rigid road projects including the case study project. In rigid pavement construction, space (joint) provided for the concrete pavement slabs was a solution given to the slabs so that they could be able to expand and contract during hot and cold temperatures until incompressible materials intrude between slabs and water infiltrating the subgrade was proved problems. Hence, to mitigate the detrimental effects of such intrusions on the performance and service life of the pavement, sealing the slab joints with sealants has become imperative. In connection with rigid pavement joint sealing practices in Ethiopia, the case study project, unlike the other three similar ongoing road projects in Ethiopia and the trends followed worldwide, has utilized a sand-bitumen mix in place of the renowned silicone joint sealants. Hence, in this research, comparative assessments on different joint sealant types (sand-bitumen mix and rubber) to replace silicone joint sealant were done. Accordingly, starting from the mix design of sand-bitumen mix with varied proportions (20/80, 25/75 and 30/70) and rubber membrane in Horizon Addis Tire laboratory, physical-mechanical properties of both sealants were evaluated in the laboratory as per ASTM standard test method. In addition, field observation was made on the case study project. As the result, unlike the sand-bitumen mix sealant which has failed all the envisaged physical and mechanical tests, the rubber membrane has exhibited incredible resistance to oil, UV, heat and abrasion. Furthermore, the rubber membrane attained an elongation, tensile, adhesion and cohesion strength, 22.2%, 7.4%, 140% and 229.2% higher than the requirement in the respective order whilst the measured hardness and compression sets were within the permissible range. Additionally, during the field observation of the case study project, different types of joint sealant failures at different severity levels (medium =75%) and (low =25%) were detected. Also, initial and maintenance cost comparisons made between the three sealants revealed that application of silicone sealant to seal the joints costs almost 200% and 1572% more than rubber membrane and Sand-Bitumen joint sealant in their respective order. Therefore, this research concluded that, from the alternative sealants, rubber membrane has endowed potential to replace the renowned silicon sealant. In addition, in this research, based on the scope and limitations of this research, recommendations were made.