Papers by Niranga Amarasingha
Science, engineering and technology, Apr 12, 2023
In developing countries with heterogeneous traffic, such as Sri Lanka, it is possible to observe ... more In developing countries with heterogeneous traffic, such as Sri Lanka, it is possible to observe severe traffic congestion at intersections and traffic corridors. The main objective of this study was to demonstrate the optimization of traffic signal controllers using VISSIM microsimulation software. It aimed to minimize traffic congestion, emissions, and fuel consumption. This study focused on developing a traffic signal controller optimization program for a congested traffic corridor which consisted of a three-legged signalized intersection, a four-legged unsignalized intersection, and a three-legged unsignalized intersection. The entire corridor was modeled here, and the already signalized three-legged intersection was optimized. Traffic signal controller optimization was done separately through the built-in optimization features in VISSIM and Webster's Method. The results showed that emissions and fuel consumption were reduced by 14.89 % in VISSIM optimization and 14.11% in optimization using Webster's Method. Through the comparison between the VISSIM optimized signal timing and manually calculated signal timing, it was found that the signal timing optimization provides much more improved results than the manual signal timing calculations. Using the proposed methodology, the traffic signal controllers can be optimized within a short duration in very few steps without any iterations compared to the existing traffic signal controller optimization techniques. Therefore, the proposed methodology is a good alternative method to optimize the traffic signal controllers.
Journal of south asian logistics and transport, Sep 24, 2021
Motorcycle is among the most popular and important modes of land transportation in tropical devel... more Motorcycle is among the most popular and important modes of land transportation in tropical developing countries like Sri Lanka. Yet, research on the effect of motorcycles on traffic safety in Sri Lanka is limited. Investigation of the risk factors and contributory causes of motorcycle crashes using data sourced from Police records was the objective of this research. Police-reported crash data in Sri Lanka contain details of crashes at all severity levels that got reported, together with their corresponding different conditions, including environment, roadway, rider, and vehicle characteristics, throughout the country. Investigating the odds-ratios, the risk factors for motorcycle crashes could be identified in developing the potential countermeasures to improve traffic safety. In Sri Lanka, during 2009-2013, more than 200,000 of motorcycle crashes have been reported. The predominant crash conditions associated with motorcycles were driving on rural roadways, during weekdays, and riding newer motorcycles. The odds-ratios indicated that riding a motorcycle on dry surface conditions, on urban roads, and using safety helmets would be much safer. The results of the study add new insights to the traffic safety literature in regard to improving road safety in Sri Lanka.
Road safety assessment is imminent to reduce road accidents in Sri Lanka. The existing road safet... more Road safety assessment is imminent to reduce road accidents in Sri Lanka. The existing road safety assessments in other countries are inapplicable to Sri Lankan Road conditions as there are significant differences between the road conditions of Sri Lanka and other countries. This study aims to identify the governing roadside elements which are influential to the cause of accidents and can be used for road star rating. The study was conducted in three districts of Sri Lanka: Anuradhapura, Polonnaruwa and Kurunegala. The data for road characteristics were obtained through the Google Earth Web engine whereas accident data were collected from Sri Lanka Police. The variables such as road condition, road length, road width, delineation, shoulder condition, footpath, vehicle parking length, road divide status, roadside objects length, number of lanes, number of intersections, number of pedestrian crossings, and number of bus bays were analyzed to develop a Negative Binomial regression model considering the number of accidents as the dependent variable. The results reveal that six variables: number of lanes, road condition, number of intersections, road divide status, road section length and width of lane are significant towards the occurrence of accidents. Moreover, the results demonstrate the relationship between the road characteristics and the accident number which is crucial in road designing in order to reduce road accidents. The findings affirm the possibility in developing a road safety rating mechanism for Sri Lankan streets to standardize the road network with the international standards while enhancing the road conditions with reflecting to the required safety levels. KEYWORDS: Road safety, Road star rating, Sri Lankan roads, Negative binomial regression
Social Science Research Network, 2023
Pedestrians engaged crashes were increased day by day in the world. There is a high risk of accid... more Pedestrians engaged crashes were increased day by day in the world. There is a high risk of accidents for pedestrians when crossing the road than walking on the road. To minimize the crash rate on pedestrians it is important to know about the risks faced by pedestrians on the road. This study aimed to report pedestrians’ perceptions of risks while walking and crossing the road. A questionnaire survey was carried out to get the data about pedestrians’ perceptions of risks while walking and crossing the road in Matara district. Data were collected with questions with a five-point scale during August and September 2021 from 225 females and 175 males. The collected data were validated by estimating the Cronbach Alpha values and analyzed using chi-square tests and multinomial logistic regression methods. The results of the study were shown the usage of that technical device while walking on the road is the most reported (66.2%) pedestrian risk in the walkways. Whereas crossing the road without using pedestrian crossings is the most reported risk (73%) during the time of crossing the road. The chisquare test results of the survey were indicated that some of the self-reported risks have a significant association with age and gender. Male pedestrians involved with risky behaviours than female pedestrians because male pedestrians have high observed values than the expected values in the reported risks. Age groups, less than 18 years and 18-30 pedestrians were mostly engaged with risky behaviours on the road. Their observed values in the pedestrian risks especially in using technical devices on the road are higher than the observed values compared to other age groups. When the average walking distance of pedestrians per day is increased, accidents happening on pedestrians is also increased. The results of this study would help infrastructure designers to make safer roads. KEYWORDS: crossing, pedestrians, self-reported risks, walking, age, gender
Social Science Research Network, 2022
Social Science Research Network, 2021
Journal of the Eastern Asia Society for Transportation Studies, Dec 31, 2019
Annual Average Daily Traffic (AADT) is one of the key parameters in the field of transportation. ... more Annual Average Daily Traffic (AADT) is one of the key parameters in the field of transportation. It is traditionally used for planning and designing purposes in road sector. This research was carried out for development of adjustment factors for AADT estimation two-way two-lane road of Colombo suburban. Malabe-Kaduwele roadway was selected to conduct the research. Data were collected using automatic traffic counter (Metro-Count device) at Malabe-Kaduwele road in front of SLIIT Malabe campus for the period of five and half months. From the data, hourly expansion factors (HEF) and daily expansion factors (DEF) were estimated. The data collection period was not sufficient to develop monthly expansion factors (MEF) but an attempt was made to develop factors for months fall in data collection period. The experience obtained in this study could be used for developing adjustment factors in future.
As the population grows, so does the need for travel. With rising demand, public transportation p... more As the population grows, so does the need for travel. With rising demand, public transportation providers are finding it difficult to meet the demand. As a result, alternative transportation services such as office transport are becoming widespread in Sri Lanka. This study aims to determine the service quality of office transport services based on user perceptions and expectations of the service. Recently there is only one study carried out in Sri Lanka focusing on office transport services. A questionnaire survey was conducted to collect data on passenger perceptions and expectations. This questionnaire survey is done within Colombo District, Sri Lanka to assess the Office transport services. Respondents were asked to rate certain qualitative characteristics of the office transport service based on their perceptions and minimum expectations of the service. In this study, Factor analysis and Structural Equation Modeling (SEM) were used to analyse the data collected through questionn...
www.trforum.org Journal of the Transportation Research Forum The Transportation Research Forum, f... more www.trforum.org Journal of the Transportation Research Forum The Transportation Research Forum, founded in 1958, is an independent, nonprofit organization of transportation professionals who conduct, use, and benefit from research. Its purpose is to provide an impartial meeting ground for carriers, shippers, government officials, consultants, university researchers, suppliers, and others seeking exchange of information and ideas related to both passenger and freight transportation. More information on the Transportation Research Forum can be found on the Web at www.trforum.org.
Journal of Advances in Engineering and Technology
Speed humps are an effective traffic calming measure to improve the safety of road users. On the ... more Speed humps are an effective traffic calming measure to improve the safety of road users. On the other hand, speed humps have certain drawbacks, such as increasing emergency response time, causing damage to cars, and high noise levels due to excessive traffic. These impacts further vary with different hump profiles. Thus, the primary objective of this research is to investigate how the geometric profile of speed humps affects vehicle speed and noise level. The secondary objective is to find the Level of Service in the presence and absence of a speed hump by using VISSIM microsimulation. In this study, Lake Drive Road, Nawala, was selected with four different speed hump profiles. The Sound Meter smartphone application was used for noise monitoring. A drone camera footage was utilized to capture vehicle flows while speed trajectories of each vehicle were developed using tracking software. The developed speed profiles were used for the simulation purpose. Then, a Multiple Linear Regres...
Transportation in developing economies, Dec 20, 2022
Proceedings of the SLIIT International Conference on Engineering and Technology, Feb 11, 2022
Proceedings of the SLIIT International Conference on Engineering and Technology
This research looks into the mobility problems that female travelers undergo, with an emphasis on... more This research looks into the mobility problems that female travelers undergo, with an emphasis on Sri Lankan women. Males and females have different social and economic roles and obligations in most civilizations, and as a result, there are major gender variations in travel and transportation demands. The aim of this research is to investigate the mobility issues of females while traveling. This research analyzes mobility problems of female travelers with special reference to the Western province of Sri Lanka. This research targets to identify the mobility barriers which affect the females’ lifestyle, the problems, and threats females have faced, and the way they go through these problems. The socioeconomic, perspective of people, and travel behavior data were collected from 450 females by using a paper-based questionnaire in August 2021. Ordinal logistic regression analysis and Chi-square test were used to analyze the data. According to the results, sexual harassment while travelin...
Asian Transport Studies, 2022
Periodica Polytechnica Transportation Engineering
Modeling effective vehicular traffic is a highly contested topic, especially in developing countr... more Modeling effective vehicular traffic is a highly contested topic, especially in developing countries like Sri Lanka, which has a wide range of driving conditions. VISSIM microsimulation software is currently used by Road Development Authority (RDA) and relevant authorities to perform traffic management solutions in Sri Lanka. However, it is required to do modifications to the existing driver behavior parameter values to effectively reflect the realistic traffic conditions observed in the real-world in the simulated model. The main purpose of this study is to calibrate the VISSIM driver behavior parameter values using a genetic algorithm (GA). The methodology and results of the VISSIM model’s sensitivity analysis and calibration, which was developed for the Malabe three-legged signalized intersection, are presented in this study. A sensitivity analysis was used to find the most sensitive driver behavior parameters. Using the multi-objective GA optimization tool in the MATLAB software...
Journal of Advances in Engineering and Technology
Hundreds of pedestrians have died and many have been injured in the past decades as a result of R... more Hundreds of pedestrians have died and many have been injured in the past decades as a result of Red Light Running (RLR) infractions. According to the United States Department of Transportation, 846 pedestrians have died and 143,000 have been injured in 2019 due to RLR violations. The majority of previous studies have focused on pedestrian behavior at an intersection, whereas only a few have looked into pedestrian RLR violations. The main objectives of this research are to find the pedestrians’ RLR rate in Sri Lanka and to find ways to reduce the RLR rate of pedestrians at the signalized crossing. Video observation surveys were conducted to collect data at three signalized intersections within Kandy city limits during weekdays for two hours per site. Pedestrian demographic variables such as gender and age; crossing characteristics such as crossing type, direction, crossing speed etc; and site characteristics such as crossing length, pedestrian green time, etc. were recorded. Chi-squa...
Journal of The Institution of Engineers (India): Series A
Proceedings of the SLIIT International Conference on Engineering and Technology
Increasing queue lengths while reducing average vehicle speeds is a notable criterion in intersec... more Increasing queue lengths while reducing average vehicle speeds is a notable criterion in intersections with heterogeneous traffic conditions. Such queue lengths vary with different intersection controls. This study aimed to estimate the queue length at un-signalized intersections with heterogeneous traffic conditions. The study was done for un-signalized intersections in Peradeniya and Weliwita, Sri Lanka and the data were collected through video recordings. The queue lengths in an un-signalized intersection with mixed traffic conditions have an instantaneous aggressive variation due to the uncontrolled movements. Thus, a time series analysis with the aid of Vector Auto Regression (VAR) model was used in order to estimate the queue length. Variables considered in this study were arrival flow rate, discharge flow rate, number of conflicts for 15 seconds time intervals as independent variables and queue length at the end of each 15 seconds as the dependent variable. For the modelling,...
Proceedings of the SLIIT International Conference on Engineering and Technology
Overtaking slower moving vehicles on the curbside under mix traffic condition is very common in S... more Overtaking slower moving vehicles on the curbside under mix traffic condition is very common in Sri Lanka. The overtaking should never be done from the curbside as a rule of thumb, also rules and regulations regarding the overtaking should be never broken by drivers. Traffic accidents statistics reveal that main cause for serious accidents in Sri Lanka are excessive speed and incorrect overtaking. However, to the best of authors’ knowledge any research about curbside overtaking behavior has not been done so far. Objectives of this study are to investigate self-reported drivers’ overtaking behavior, and to find out drivers’ perspective about current rules and regulations on overtaking. A questionnaire form was developed, and a survey was conducted to collect data among 430 people in Colombo district. Chi–square tests and multinomial logistic regression analysis were done. Chi – square test results showed that among the selected variables, gender, age, occupation, driving license avai...
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Papers by Niranga Amarasingha