COLLECTIONS

JOURNALS

Documents published in Scipedia

• Performance Evaluation of Grade Separation Within the Selected Major Intersection in Addis Ababa City

  S. Leleisa, E. Quezon, T. Wedajo

  American Journal of Traffic and Transportation Engineering (2018). Sentayehu Leleisa, Emer Tucay Quezon, Teyba Wedajo. Performance Evaluation of Grade Separation Within the Selected Major Intersection in Addis Ababa City. American Journal of Traffic and Transportation Engineering. Vol. 3, No. 3, 2018, pp. 41-49. doi: 10.11648/j.ajtte.20180303.11

  
  

  Abstract

  Urban City Traffic Management introduced various remedies to decongest traffic and to reduce the severity of accidents, such as providing traffic signal controls at the intersecting roads at different levels, or grade separating the traffic movement towards different directions. One type of grade separation is Road Underpass or Flyover. The construction of Road Underpass or Flyover poses some doubts whether it is effective or ineffective from the point of view of the travelers or motorists. It is for this reason that this research sought to evaluate the performance and effectiveness of the Road Underpass structure on traffic flow at the major intersection, specifically the Wellosefer intersection in Addis Ababa City. The primary data used the existing traffic volume recorded between 7:00 AM – 6:00 PM from Monday to Friday. While the secondary data obtained from the Consulting Office 'before' the improvement of Wellosefer intersection, including the previous study, which served as the control analysis for the research. From these data, the analyses provided results on vehicle travel time and delay for a case 'before' and 'after' improvement of the intersection. SIDRA Software was used to analyze the traffic conditions of the intersection. Based on the findings of the study, a case 'before' Improvement of Wellosefer Unsignalized T-Intersection indicated an average delay of vehicles of about 535.7 seconds and a travel time of vehicles of about 574.7 seconds. On the other hand, in a case 'after' Improvement of Wellosefer intersection, three alternatives considered; such as 1) Signalized T-Intersection, 2) Roundabout and 3) Road Underpass with Roundabout at the upper level. The results of the first alternative showed the Signalized T-intersection indicated an average delay and travel time of 344.3 seconds and 365.0 seconds, respectively. It means, there could be a reduction of 15.4% in average delay if signalized intersection implemented. The second alternative, a case of Roundabout using the same traffic data at current condition, the results indicated the motorists and commuters would be experiencing an average delay of about 355.8 seconds and average travel time of 390.0 seconds. The third alternative considering Road Underpass with Roundabout at the upper level, the results revealed that there was a significant reduction in an average delay of vehicles of about 42% from the Unsignalized T-Intersection. Comparing this result with the Signalized intersection using the same traffic data, showed that there was a significant decrease in average delay. Therefore, the findings of the study, a combination of Road Underpass and Roundabout at the upper level as in the case of Wellosefer intersection performed well than the other traffic control design alternatives.

  Abstract
  Urban City Traffic Management introduced various remedies to decongest traffic and to reduce the severity of accidents, such as providing traffic signal controls at the intersecting [...]

  • 6
  •  read

• Traffic Safety Evaluation at Unsignalized road Intersection using Proactive Approach

  . Abstract, E. Quezon

  Proceedings of the 2nd Annual Ethiopian Road Safety (RSC2018) (2018). Seifeddin Haji, Prof. Emer T. Quezon, Murad Mohammed, Biruk Yigezu. Traffic Safety Evaluation on Urban Road Un-signalized Intersection using Proactive Approach: A Case Study in Adama City. Proceedings of the 2nd Annual Ethiopian Road Safety (RSC2018) Addis Ababa, Ethiopia, August 23-24, 2018

  
  

  Abstract

  Deaths and injuries as a result of road accidents are a recognized global problem and authorities are aware of the consequences this global phenomenon might lead to. Because of the rapid development of urbanization and motorization in developing and transitional countries, like Ethiopia, actions to improve traffic safety conditions are urgently needed. Highway intersections are among the greatest safety challenges because they are some of the most common highway features. Improving the safety level of the urban intersection is an important way to increase safety. Safety evaluations can help to develop effective safety countermeasures to lower crash rates and reduce crash severity. So how to diagnose safety problems and improve urban road intersection safety effectively becomes an important issue. Now, there have been quite a number of safety analysis methods and theories in the city intersection, but these methods and theories are formed on the basis of traffic accidents. However, the data on traffic accidents is not accurate enough, these theories are not appropriate for our country. Also, it is impractical and unethical to wait for accidents to occur before being able to draw statistically sound conclusions regarding safety improvement. Hence there is a need to develop a proactive approach, a non-accident-based approach, to evaluate urban road Unsignalized intersection safety performance. A proactive approach (indirect and non-accident based approach) was attempted to that of traditional reactive approach (direct and accident based approach) which is purely based on the existing conditions that have direct relationships or impacts to traffic safety such as the geometric, traffic control & engineering, road Surface and environment characteristics. The non-accident-based approach is based on field surveys under the conditions mentioned previously, summarizes the intersection safety diagnosis in a safety index to indicate the safety performance of the intersection. The study indicates that the proposed methodology and intersection safety diagnosis technique can be used to perform an evaluation of traffic safety and improvement at an intersection even when there are few resources available. Also, the use of intersection safety diagnosis is a more resource-efficient and ethically appealing alternative for fast, reliable, and effective safety assessment.

  Abstract
  Deaths and injuries as a result of road accidents are a recognized global problem and authorities are aware of the consequences this global phenomenon might lead to. Because [...]

  • 22
  •  read

• Investigation of Pedestrian Safety Problems and Its Countermeasures: A Case Study in Nekemte City, Ethiopia

  H. Alemgena, P. Quezon, T. Kumela, E. Quezon

  International Journal of Engineering and Technical Research (2018). Alemgena, H.; Quezon, ET.; Kumela, T. Investigation of Pedestrian Safety Problems and Its Countermeasures: A Case Study in Nekemte City, Ethiopia. International Journal of Engineering and Technical Research. 2018; 8(2): 58-64

  
  

  Abstract

  The actual growth of urban economic activities and simple movements of peoples and goods measured through its primary transport system. The requirements of the pedestrian should be considered in the design of the urban environment and transportation facilities. Since road infrastructure improvements and designed pedestrian environments are an essential part of road safety enhancements that increase walking and decrease fatalities. This study investigated the pedestrian safety problems and its countermeasures on road segments in Nekemte city. This study examined the existing issues affecting the safety of pedestrian movement, evaluates the service quality of walking facilities, and finally identified the most significant factors affecting pedestrian safety with engineering countermeasures in the city. For the data analysis, the study used both objective measurements and subjective assessments to model PLOS using Australian methods. As per field study indicates 60% of the respondents' think the sidewalk is not user-friendly. In the city, the built road infrastructure is lacking pedestrian facility management and appropriate maintenance activities. Since the walkways in Nekemte city, in general, have almost the same problems like non-continuous, crack, and non-covered utility holes which are difficult especially for pedestrians with disabilities. The current sidewalk is encroached either by vendors, utility poles, parking carts or illegal construction materials in different places, and crosswalk facilities are not visible and not enough provided at a logical distance. The Pedestrian LOS analysis indicates that poor pedestrian conditions exist and the factors that negatively affect pedestrian LOS are wide-ranging in this city road segment. It concluded that Pedestrian facilities and all the concerned factors should be provided and maintained to more efficient for both encouraging people to walk and improve pedestrian safety.

  Abstract
  The actual growth of urban economic activities and simple movements of peoples and goods measured through its primary transport system. The requirements of the pedestrian [...]

  • 24
  •  read

• Analysis of StressStrain and Deflection of Flexible Pavements Using Finite Element Method Case Study on Bako-Nekemte Road

  S. Wayessa, E. Quezon, T. Kumela

  Journal of Civil, Construction and Environmental Engineering (2017). Shiferaw Garoma Wayessa, Emer Tucay Quezon, Tarekegn Kumela. Analysis of Stress- Strain and Deflection of Flexible Pavements Using Finite Element Method Case Study on Bako-Nekemte Road. Journal of Civil, Construction and Environmental Engineering. Vol. 2, No. 4, 2017, pp. 100-111. doi: 10.11648/j.jccee.20170204.11

  
  

  Abstract

  In Ethiopia, the failure of roads is before the handover period. Most roads found in Ethiopia are flexible pavements. Nowadays, the failure of the surface of flexible pavement roads is common before the expected design period. For example, the Bako-Nekemte road/ has become a critical issue in our country. The most common parameters that cause stress, strain, and deflection of the roads are loads and pressures that come from vehicles. Moreover, the modulus of elasticity, Poisson’s ratio, and thickness of each layer need to be characterized. Further, the load magnitude, contact pressure (or load radius), and location are defined for each load (wheel) considered. The finite element method (FEM) is a numerical analysis technique to obtain the stress-strain and deflection of each pavement layer. The analytical method usually uses layers thickness, loads, elastic modulus, and Poisson’s ratio of the pavement materials as design parameters. The objective of this research was to study the sensitivity of the road parameters in analyzing the major causes of failure in asphalt pavement layers fatigue cracking and rutting deformation which came due to the critical tensile strains at the bottom of the asphalt layer and the critical compressive strains on the top of subgrade using the finite element method by relating the standard specification of ERA and laboratory test result. This thesis studied the analysis of stress-strain and deflection of flexible pavements using the Everstress finite element method. The Ever stress program will take into account any stress-dependent stiffness characteristics. This thesis dealt with ways to reduce deflections by varying the design configuration, such as increasing the HMA modulus, the base modulus, sub-base modulus, the subgrade modulus, and increasing the thickness of each layer. Based on the type of materials to use the value of elastic modulus and poison’s ratio are various in each layer, in layer 1 is varied from 1500 to 3500 MPa, in layer 2 is varied from 200 to 1000MPa, in layer 3 is varied from 100 to 250 MPa and in layer 4 is varied from 20MPa to 150MPa.

  Abstract
  In Ethiopia, the failure of roads is before the handover period. Most roads found in Ethiopia are flexible pavements. Nowadays, the failure of the surface of flexible pavement [...]

  • 32
  •  read

• Calcined Termite Hill Clay Powder: As Partial Cement Replacement in Production of C-25 Grade Concrete

  G. Danbala, E. Quezon, G. Kebede

  American Journal of Civil Engineering and Architecture (2019). Guyo Konso Danbala, Emer Tucay Quezon, and Getachew Kebede, “Calcined Termite Hill Clay Powder: As Partial Cement Replacement in Production of C-25 Grade Concrete.” American Journal of Civil Engineering and Architecture, vol. 7, no. 3 (2019): 128-134. doi: 10.12691/ajcea-7-3-2.

  
  

  Abstract

  Cement is one of the components of concrete plays a great role in the construction industry. Nevertheless, it is the most expensive and environmentally unfriendly material. Therefore, requirements for economical and more environmentally-friendly cementing materials have extended interest in other cementing materials that can be used as partial replacement of the ordinary Portland cement. This research was, conducted to examine the suitability of calcined termite hill clay powder as a cement replacing material in the production of C-25 grade concrete as a relief for this problem. The Termite Hill Clay sample was collected from Bokuluboma vicinity. The sample was calcined at the temperature of 650°C using muffle furnace, ground to the fineness of 150 µm and its chemical composition was investigated. Normal consistency and setting time of the paste having Ordinary Portland Cement and calcined termite hill clay powder from 0% to 40% replacement in 5% increment percentage investigated. The compressive strength of eight different concrete mixes with the CTHCP replacing the ordinary Portland cement prepared for 22MPa and 34MPa (i.e., for 7th and 28th days targeted compressive strength) concrete with water cement ratio of 0.5 and 360kg/m3 cement content. The properties of the mixture assessed both at the fresh and hardened state. Results revealed that calcined termite hill clay powder found pozzolanic and can partially replace cement. It has shown that up to 11.3% replacement of the ordinary Portland cement by CTHCP, the cubes achieved a target mean compressive strength of C-25 grade concrete at 28th day 34Mpa. Although, the replacement percentage greater than 11.3% of the cement of calcined termite hill clay powder in the concrete has shown a slightly lower compressive strength. Moreover, the mix indicated workable up to 25% replacement percentage and also the setting time of the paste containing calcined termite hill clay powder found faster than that of the control mix. Hence, it is concluded that CTHCP was suitable to replace cement partially with 11.3% replacement of cement by calcined termite hill clay powder as the optimal percentage of the production of C-25 grade concrete. The fresh concrete mix was workable up to 25% replacement, and the mineral admixture served as an accelerator which is suitable for cold weather concreting works.

  Abstract
  Cement is one of the components of concrete plays a great role in the construction industry. Nevertheless, it is the most expensive and environmentally unfriendly material. [...]

  • 12
  •  read

• Evaluation of the Performance of Brick Dust as a Filler Material for Hot Asphalt Mix Design A Case Study in Jimma Zone

  F. Wagaw, P. Quezon, A. Geremew, E. Quezon

  The International Journal of Engineering and Science (2018). Fisseha Wagaw, Prof. Emer Tucay Quezon, Anteneh Geremew. Evaluation of the Performance of Brick Dust as a Filler Material for Hot Asphalt Mix Design: A Case Study in Jimma Zone. The International Journal of Engineering and Science. 2018; 7(3): 64-72. DOI:10.9790/1813-0703026472

  
  

  Abstract

  A bituminous paving mixture is a mixture of coarse aggregate, fine aggregate, and bitumen mixed in suitable proportion to result in a strong and durable mix in order to withstand traffic load. In this paving mix, ordinary stone dust, and cement used as filler material. One of the main problems in the construction of a bituminous paving mixture is the insufficient amount of filler from crushing stone aggregate, and cement supply is low. A study has been carried out in this research to explore the use of Brick dust as filler material for the bituminous mixture. The objective is intended to evaluate the performance of brick dust as fillers in Hot Asphalt Mix design, according to the test procedure specified by ASTM. Several specimens of hot asphalt mixture were prepared according to ASTM D 1559 using an aggregate blend with brick filler and aggregate blend without brick filler. The aggregate blending made by using Job mix formula to obtain the percentage of mixed material. For aggregate blended without brick G-1 32%, G-2 23%, and G-3 45% for Aggregate blended with brick filler G-1 30%, G-2 18%, G-3 45% and G-4 7%; where G-1 Coarse Aggregate 3/4, G-2 Coarse Aggregate 3/8, G-3 Fine Aggregate, and G-4 brick filler. It concluded that the results of the Marshall test of mix design showed satisfactory when hot asphalt mixed with these brick fillers. The Specimens blended with brick filler lead produce asphalt mixture with higher Marshall stability, lower flow, a less void filled with asphalt. Hence, brick dust can replace stone dust and cement filler in the bituminous paving mix. It is recommended to use brick dust as filler material in a bituminous paving mix may save considerable investment; as well as a reliable performance of the in-service highway can be achieved.

  Abstract
  A bituminous paving mixture is a mixture of coarse aggregate, fine aggregate, and bitumen mixed in suitable proportion to result in a strong and durable mix in order to withstand [...]

  • 11
  •  read

• International Journal of Scientific & Engineering Research

  E. Quezon

  International Journal of Scientific & Engineering Research (2016). Tarekegn Kumala, Prof. Emer T. Quezon, Bogale Shiferaw. Effect of Cycle Time and Signal Phase on Average Time Delay, Congestion and Level of Service: A Case Study at Hager Astedader Signalized Intersection in Addis Ababa. International Journal of Scientific & Engineering Research. 2016; 7(10): 524-530.

  
  

  Abstract

  High urbanization rate and Economic development have caused many challenges to transportation systems. Among these, long time delay and high fuel consumption of vehicles at congestion places are a few to mention. Some literatures have revealed that road traffic congestions are caused by inadequate infrastructures, long signal cycle time, and poor traffic management, such as incapable roads, inefficient public transit, and high travel demand. The research study was focused on the effect of traffic congestion on average time delay at a selected signalized road intersection in Addis Ababa. The study area was the Hager Astedadrerroad traffic signal intersection. The methodology that has been employed for the study was a quantitative descriptive research design method. The data needed were; road geometry data, signal data, traffic vehicles flow data including the pedestrian data were collected on-peak hours (with 15minutes intervals) from 7:30 to 9:30 AM and from 5:30 – 7:30 PM for the four consecutive working days. Data of traffic classes were extracted manually on a separate worksheet. The volume of each vehicle category was converted to the same vehicle category using the passenger car unit (PCU) of each vehicle class. Data analysis and processing have been performed using SIDRA (Signalized and Unsignalized Intersection Design and Research Aid) intersection software in order to know the traffic flow condition at the intersection. The result of average time delay was used to know the corresponding level of service and operational performance of the intersection. The outcomes of the research work minimize average time delay by adopting different improving strategies that range from low-cost measures such as improvements to signal timing and phase numbers, to high-cost measures such as intersection reconstruction, which be applied in the study area after knowing the amount of average time delay as well as the types of the level of service within the intersection area. 

  Abstract
  High urbanization rate and Economic development have caused many challenges to transportation systems. Among these, long time delay and high fuel consumption of vehicles at [...]

  • 233
  •  read

• Regression Analysis of Index Properties of Soil as Strength Determinant for California Bearing Ratio (CBR)

  D. Abdella, T. Abebe, P. Quezon, E. Quezon

  GSJ (2017). Dino Abdella, Tadesse Abebe, Prof. Emer Tucay Quezon. Regression Analysis of Index Properties of Soil as Strength Determinant for California Bearing Ratio (CBR). GSJ. 2017; 5(6): 1-12

  
  

  Abstract

  Investigation of the variation in different soil types and origins is an essential task for Geotechnical engineers. To overcome the effects of this change, the Geotechnical engineers, as well as other professionals, attempted to develop empirical equations unique to a region and soil type to use the soil for its intended purpose. However, these empirical equations are more reliable for the kind of soil where there is a strong relationship of parameters is developed. Hence, it is good practice to develop empirical equations that best fit the soil available in the location that we can access. On the flexible pavement, the subgrade is considered to be an ideal layer to resist wheel load, and its CBR value is considered as the strength measuring a parameter. Conducting a CBR test is an expensive and time-consuming procedure. Also, it is challenging to mold the sample at a desired in-situ density in the laboratory. Furthermore, if the available soil is of poor quality, suitable additives are mixed with soil, and the resulting strength of the soil is assessed by the CBR value which is cumbersome. To overcome such a problem, statistical approaches such as regression-based models are used. This can be used for quick and easily determined parameters. Relative to this, the study has been conducted to develop an equation to show the relationship between the index properties and CBR values precisely located along WelkiteArekit –Hosanna Road of about 121km stretches. It was carried out using thirty samples retrieved from this road and tested in a laboratory. The test result of the regression-based statistical analysis was used to develop the predetermined relationship. The relationship development was performed in the form of an equation of CBR as a function of grain size parameters, Atterberg’s liquid limits, and compaction parameters by considering the effect of individual soil properties as well as the effect of a combination of soil properties on the CBR value. Based on the results of the study for both linear and multiple linear regression analyses, it was revealed that there was a relatively fair relationship obtained by combining plasticity index, the percentage of fine content, and maximum dry density which are strength determinants of fine-grained soils. Also, the results showed that the coefficient of determination for multiple linear regression is R2=0. 731, while for single linear regression is R2=0. 682. Therefore, it is concluded that the index properties of soils are sufficiently accurate in determining the CBR values, of which it can be utilized for preliminary characterization.

  Abstract
  Investigation of the variation in different soil types and origins is an essential task for Geotechnical engineers. To overcome the effects of this change, the Geotechnical [...]

  • 21
  •  read

• Effects of human behaviors and geometric factors in road traffic accidents a case study along Sululta-Fiche road, Ethiopia

  E. Quezon

  GJS (2017). Galeta Chala, Prof. Emer Tucay Quezon, Tarekegn Kumela. Effects of human behaviors and geometric factors in road traffic accidents: a case study along Sululta-Fiche road, Ethiopia. GSJ: 2017; 5(11). 163-172

  
  

  Abstract

  A road traffic accident was one of the severe problems which are affecting once’s a country and leading to death, injuries and property damage resulted in economic loss. The objective of this research was to investigate the effects of Human behaviors and Geometric factors in road traffic accidents along the road of Sululta-Fiche, which is located in the Northern Shewa of the Oromia region. Both probability sampling and non-probability sampling techniques were applied. The primary data were obtained from site observation of blackspot locations. While the secondary source of data was taken from records compiled by the North Shewa traffic office and Oromia Special Zone Surrounding Finfinne traffic Office. Descriptive and analytical design methods were used in this research, while the results were displayed by graphs, tables, and pie charts. From the study, the status of road traffic accidents showed that there were dramatically increase in accidents every year within the study period. A total of 830 crashes occurred in the past three years. From this, 237 accidents happened in 2012, 279 accidents in 2013, and 314 accidents in 2015. From the traffic police report analysis, there were 41 locations in Sululta Town, and 70 locations in Sululta Wereda, where those accidents happened. Based on the results of this research using the priority value approach, there were 12 selected locations in Sululta Town and 10 chosen locations in Sululta Wereda. Therefore, it is concluded that the significant factor in traffic accidents along Sululta –Fiche road was the driver errors such as over-speeding, night driving, and driving without attention, and it was followed by the geometric factors. These road deficiencies contributory to some errors of the drivers, which were inadequate road width, insufficient sight distance, and narrow bridge at sag curves, and improper intersection design. Based on the findings of the study, some of the countermeasures recommended reducing the road traffic accidents are the provision of speed limit signs to forewarn drivers, installation of speed barkers and rumble strips, widening the lane width of pavement, maintenance of the deteriorated road, repair of the road signs and provision of adequate sight visibility for drivers.

  Abstract
  A road traffic accident was one of the severe problems which are affecting once’s a country and leading to death, injuries and property damage resulted in economic loss. [...]

  • 10
  •  read

• Effectiveness of using Geosynthetic Material for Improvement of Road Construction and Performance Case Study on Adis Ababa

  M. Gurara, K. Getachew, E. Quezon, E. Quezon

  International Journal of Engineering Research & Technology (2017). Mikiyas. J Gurara, Kabtamu Getachew, Emer Quezon. Effectiveness of using Geosynthetic Material for Improvement of Road Construction and Performance - Case Study on Adis Ababa. International Journal of Engineering Research & Technology. 2017; (6)2: 640-642

  
  

  Abstract

  The research is concerned with the Effectiveness of geosynthetic to improve the performance of the pavement. It has been done on road construction projects under Addis Ababa Road Authority. Results indicated that the performance of bottom pavements structures constructed on poor subgrades with CBR values not greater than 4% was significantly enhanced using geosynthetic material. An increase of bearing capacity for subgrade and can improve the subgrade quality without excavating and filling of select material only by using geomembrane. Geosynthetic reinforcement in pavement design and construction should be widespread. Geosynthetic reinforcements are incorporated into permanent, paved roads either as base (or subbase) reinforcement - in flexible pavements to aid in the support of vehicular loads over the life of the pavement; or as subgrade restraint for construction of flexible or rigid roadways over weak subgrade conditions to aid in support of equipment loads on the unpaved base, or subbase, course during construction. Clearly, both base reinforcement and subgrade restraint with geosynthetics are proven techniques for use in pavement design and construction effectively.

  Abstract
  The research is concerned with the Effectiveness of geosynthetic to improve the performance of the pavement. It has been done on road construction projects under Addis Ababa [...]

  • 4
  •  read