Browsing by Author "Wannige, EP"

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item: Conference-Abstract
Evaluating the impacts of coordinated traffic signal systems
(Department of Civil Engineering, University of Moratuwa., 2015-08) Wannige, EP; Bandara, JMSJ; Pasindu, HR
Traffic congestion due to ever-increasing number of vehicles and pedestrians is one of the major problems that need to be tackled especially in metropolitan areas. Numerous methods are available to reduce delays and financial losses as well as environmental problems caused by road traffic in major cities. Signalizing is one of the main methods to control traffic at intersections. Most of the signalized junctions Sri Lanka are isolated fixed-cycle type. Signal coordination is considered as one of the cost effective and successful strategies to reduce congestion problems worldwide. When traffic signals work together (or are coordinated), they provide a greater opportunity for motorists to travel through adjacent traffic signals without making unnecessary stops. This reduces fuel use, saves motorists travel time, diminishes wear and tear on vehicles, and cuts vehicular emissions. Sri Lankan road development and management agencies are in their planning stage to implement this system for signalized intersections. However, little has been done to quantify the benefits that can be obtained from coordinated traffic signal systems. Although it is important to have quantified measure of the benefits compared to prevailing system, such measure is not yet available in Sri Lankan context. Therefore, objective of this research is to evaluate the benefits from Traffic signal coordination in reducing delay and reducing travel time to vehicles. As a case study, closely spaced three signalized junctions are selected at for the analysis. The junctions selected are Park Road Junction, Narahenpita Junction and Kirimandala Mawatha Junction on Baseline Road. SIDRA, Signalized (and unsignalized) Intersection Design and Research Aid is used to generate the timing plans for each junction. Each junction is analyzed considering as a non-coordinated isolated junction and also as an individual junction of a coordinated system. Travel time, delay, effective stop rate and proportion queued are identified as important parameters to evaluate the benefit/impact of the coordinated system. Data related to above parameters taken from the SIDRA output is used to calculate the travel time and delay of the coordinated system and in the isolated system separately. Using the evaluation results, travel time saving, reduction of delay and reduction of stop rate are presented as percentages, as quantified measures of the benefits of the signal coordination. Limitations of signal coordination such as time for pedestrians, non-uniformity of intersections are identified and evaluated to take a quantified measure of the negative impacts of the system.
item: Thesis-Full-text
Evaluating the impacts of coordinated traffic signal systems
Wannige, EP; Bandara, JMSJ
Traffic congestion due to increasing number of vehicles and pedestrians is one of the major problems that need to be tackled especially in urban areas. Numerous methods are available to reduce delays and financial losses and environmental problems caused by road traffic in major cities.Signalizing is one of the main methods to control traffic at intersections. Most of the signalized junctions in Sri Lanka are isolated fixed-cycle type. Signal coordination is considered as one of the cost effective and successful strategies to reduce congestion problems worldwide. Sri Lankan road development and management agencies are in their initial stage of implementing this system for signalized intersections. However, little has done to quantify the benefits that can be obtained from coordinated traffic signal systems and hardly done studies to recommend a suitable guideline for Sri Lankan context. Therefore, objective of this research is to evaluate the impacts from traffic signal coordination in reducing delay and queue length and propose a guideline, which can be used in signal coordination in Sri Lankan context in optimized manner. As a case study, closely spaced three signalized junctions are selected at for the analysis. SIDRA, Signalized (and unsignalized) Intersection Design and Research Aid is used to generate the timing plans for each junction. Manual calculations are also done. The system was modeled using PTV VISSIM software and each junction is analyzed considering as a non-coordinated isolated junction and as an individual junction of a coordinated system using that software model. Travel time, delay, effective stop rate and queue length are identified as important parameters to evaluate the benefit/impact of the coordinated system. Data related to above parameters taken from the VISSIM output is used to compare coordinated system and in the isolated system. Using the evaluation results, reduction of delay and reduction of queue length are presented as percentages, as quantified measures of the benefits of the signal coordination. Limitations of signal coordination such as time for pedestrians, longer waiting time to minor street traffic are also identified during the study. Various coordination strategies were modeled as both direction coordination, single direction coordination, multiple cycle times etc. Using the results of the case study, a proper methodology is proposed to optimize the signal coordination in a considered set of junctions.
item: Conference-Abstract
Guideline for the selection of appropriate specifications for low volume roads
(Department of Civil Engineering, University of Moratuwa., 2010) Wannige, EP; Abeywardena, HST; Haththotuwa, HMDS; Bandara, JMSJ; Pasindu, HR
The paper presents the research carried out to prepare a set of guidelines for the selection of appropriate specifications for low volume roads. It is an essential requirement to have such a guideline because lack of such guideline has resulted in waste of valuable resource in road construction work. This research finding are very important to Sri Lanka as there are many problems associated in the low volume roads due to lack of technical knowhow of the majority of people involved in the low volume road construction and maintenance. This paper describe the work is carried out in order to provide a guideline to minimize existing problems. For the purpose of selecting suitable specifications for low volume roads a wide range of data base was needed. Areas selected for data collection were Badulla, Diyathalawa and Mahiyanganaya Engineering divisions in Uva Province. With the purpose of having a good database for analysis, data was collected through both discussions with engineers in provincial Road Development Department in Uva Provincial Council and observed data through field visits. Practice of low volume road planning, design and material selection, construction and maintenance were discussed with engineers and important road sections for visits were identified. Through field visits data on various parameters affecting the road condition were collected including all road types such as DBST, gravel, concrete and metalled & tar. The data collected was statistically analyzed using SPSS software to identify significant relationships are present between parameters identified as important. The identified important parameters were drainage condition, traffic volume, terrain, land use, material used and carriage way width. Crosstab analysis was carried out between two parameters and also in between more than two parameters using layer option available in SPSS. Results of the data analysis were used for producing the set of guidelines for planning, design and material selection, and construction and maintenance phases. A GIS map was also produced to indicate the existing road conditions as a tool for identifying access needs during planning process of roads. A sample inventory of road infrastructure is presented to demonstrate how to use collected information during planning, design, and construction and operation stages of low volume roads.
item: Conference-Extended-Abstract
Identification of parameters affecting the road condition in low volume roads
(2010) Wannige, EP; Haththoiuwa, DS; Abeywardena, TS; Bandara, S
It is an essential requirement to identify parameters affecting the road condition and give solution to the problems in low volume roads, because lack of such knowledge has resulted in many problems and waste of valuable resources. For the need of wide database, data was collected through discussion with Engineers, and observed data from field visits in Badulla, Diyathalawa and Mahiyanganaya and Wellawaya Engineering divisions. These data were statistically analyzed using SPSS software to identify significant relationships between parameters considered. The identified important parameters affecting the road condition were drainage condition, traffic volume, terrain, land use, material used and carriage way width. These parameters were prioritized in producing the set of guidelines for planning, design and material selection, and construction and maintenance phases. A GIS map was also produced to indicate the existing road conditions as a tool for identifying access needs during planning process of roads. A sample inventory of road infrastructure was prepared to demonstrate how to use collected information during planning, design, construction and operation stage of low volume roads.