Browsing by Author "De Silva, D"

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item: Conference-Abstract
Analysis on transport mode choices of school children in Colombo District, Sri Lanka
(Department of Civil Engineering, University of Moratuwa, 2020-12) Damsara, P; De Silva, D; Sirisoma, N; Perera, HLK
The increase in the usage of private transport modes for school trips has become a major reason for traffic congestion in Colombo District during peak hours. Colombo District consists of 402 functioning government schools, with a total student population of 374,995. Those schools have been categorized into four categories based on the availability of classrooms. According to the Ministry of Education, there is a limitation which is imposed on the distance from home to school, in the student enrollment process. However, it has been identified that the distances are exceeding the limitation, with respect to the school type and location. As a result, students choose different transport modes based on many factors such as accessibility, connectivity, safety, reliability and comfort. This study focuses on identifying the distances from home to school and the respective transport mode choice of the students in Colombo District. In addition, the factors which affect those school children to avoid public transport modes were analyzed. The quantitative research approach has been used in developing the research methodology in several phases such as factor identification, mode choices and demand distribution. Data collection has been conducted through a questionnaire survey which covers 28 selected schools under four categories, with a total sample size of 2875 in all Divisional Secretariat Divisions (DSDs) of Colombo District. Stratified sampling technique was used to collect data from the above school types. Schools which have classes in all streams up to advanced level (1AB schools) show the highest percentage of students (44%) who travel a distance of 2-10 km from home to school, while other school types show the highest percentage of students (49%) who travel a distance range of less than 2 km. Further, it has been identified that 1AB schools have some students who travel more than 25 km daily for their school trips. School van/bus services are the main mode of transport which is used by the students of schools located in Colombo Municipal Council (CMC) area, while public transport modes such as bus, train and “Sisu-Sariya school bus service” are the main modes of transport which are used by the students outside the CMC area. Active transport modes are the least popular mode of travel in both CMC and Non-CMC area (13% each), while private transport modes, which consists of car/van/jeep, motorbikes and three-wheelers contribute 25% in CMC area and 33% in Non-CMC area. Furthermore, it has been identified that longer travel times, longer waiting times, poor accessibility, less security and less comfort are the main reasons for the students in Colombo District, to not use public transport services. Even though there is a dedicated public transport service (“Sisu-Sariya”), which have been provided for school children, it has been found that there is a considerable usage of private transport modes for school trips in the district. Therefore, this study recommends a procedure to develop an improved public transport system for school trips including a model for trip distribution patterns, network connectivity and system planning to attract more students into public transport services.
item: Conference-Abstract
An application of a cell transmission model using crowdsourced data for expressway monitoring
(Department of Civil Engineering, University of Moratuwa, 2021-11) Wijepala, WMRV; De Silva, D; Hettiarachchi, P
With the increasing traffic congestion in alternative roads, the demand for expressways is increasing rapidly in Sri Lanka. With this increase in demand, traffic management systems are needed for expressways. Deviating from traditional expensive methods of traffic data collection, a more economical and reliable data collection method is needed for developing countries. This study aims to develop and apply a Cell Transmission Model which was first introduced by Carlos F. Daganzo in 1993. The crowdsourced traffic data collected by Google Distance Matrix API has been used. An expressway section was selected and divided into number of sections referred as cells, which were defined with different cell lengths according to the location of the expressway section. The average speed of each cell was collected from Google maps using the MTRADA platform to identify the traffic condition of the selected expressway section, every 5 minutes. The speed data collected were represented in a spatiotemporal graph. Different cell lengths were tested to identify the optimum cell lengths for the model that would allow to identify variations in speed changes. A manual flow data collection was also collected to study the trend between manually collected flow data and speed data collected from M-TRADA. 2 types of cells were used as 200 m and 250 m as normal cells and 400 m and 500 m as doubled cells. Data were collected for both the types simultaneously. According to the comparison done for both the cell types, the normal cells show sufficient information of speed changes than the doubled cells and the cell size has to be at minimum 200 m at the on/off ramps, near sharp curves and near interchanges, while a cell size of 250 m would be sufficient to for cells within the main lanes. This model is more useful for expressways with higher demand. A user interface is proposed for a web application that can be developed using this model for real-time traffic monitoring purposes. Because of the simplicity of the model, even non-expert users will be able to use this web application.
item: Conference-Abstract
Applying Built – Operate - Transfer (BOT) systems for Sri Lankan expressways: a case study
(Department of Civil Engineering, University of Moratuwa, 2020-12) Perera, AP; De Silva, D; Perera, HLK
Sri Lankan transport network had a massive development during the last decade experiencing highway infrastructure, with the utilization of foreign concessions and local government funds of the country. Road Development authority holds the pioneering authority to operate and maintain the highway and expressway network in periodically. The user benefits generated with the road network are travel time saving, developed infrastructure and living standards also with the social benefits which are not counter measured in quantitatively. As a developing country, a lack of financial stability for the infrastructure of the government may lead to foreign loans and concessions. The concessions lead to rapid involvement in the fund involvement for mega infrastructure projects as the necessity and demand of the country. The Build-Operate-Transfer (BOT) concession model is becoming a major trend in the privatization of infrastructure projects and the concession period and interest rate are critical parameters for BOT contracts. In this study, a model is developed to demonstrate the potentiality of applying BOT system for the expressway network of the country. The demand estimation, operation and maintenance cost and toll revenue used as the inputs for this model and financial viability is observed with different scenarios. The concession period, interest rates and optimality of selection of BOT are decided with different criteria based on financial viability. As the Colombo-Katunayaka Expressway (CKE) meets the highest demand for traffic in the expressway network, inputs of CKE used to demonstrate the potentiality of applying BOT model and optimum subsidy level was determined with the application of variable concession periods. This BOT model is further developed to validate any expressway network in urban or suburban basis by considering traffic demand with the considerations of unit length costs and revenues in operations with the performed analysis for existing and proposed expressways in Sri Lanka The urban and sub-urban links were defined for expressways, by considering the actual traffic demands between each intersection of Outer Circular Highway (OCH), Southern Expressway and forecasted traffic on ongoing Central Expressway and proposed Ruwanpura Expressway and costs and revenue per unit length were determined for each link in respectively by applying actual data.
item: Conference-Abstract
Automating the initial configuration of sdn switches in a hybrid-sdn environment
(Information Technology Research Unit, Faculty of Information Technology, University of Moratuwa., 2022-12) Bolonghe, WKN; Rupasinghe, PM; Umayanga, KSB; Weerasiri, KLHI; De Silva, D; Wijesiri, P; Sumathipala, KASN; Ganegoda, GU; Piyathilake, ITS; Manawadu, IN
At present for SDN environments, there are many proposed mechanisms to improve its reliability, and performance. The challenges faced by SDN networks are mainly related to Scalability, Reliability and Performance. As an example, for scalability related challenges, many SDN networks have problems when replacing or installing new SDN switches to the network. The problems are mainly the cost and errors while the installation process. To overcome this issue, a mechanism is proposed to automate the initial configuration of the newly added SDN switches. When it comes to the performance, there are problems such as load balancing, looping and traffic related issues due to broadcast messages. To minimize these challenges the project also brings solutions by implementing DHCP relays and STP inside the network. Also, with the multi-controller architecture proposed it increase the efficiency and Performance. To automate the initial configuration of the switches, the newly added switch is detected at first and then a relationship is established between the newly added switch and an existing SDN switch. Then the newly added switch establishes a connection with the automation server, which then results the automation process to start. The proposed mechanism is implemented in a testing environment using Mininet which creates a virtual environment, a RYU controller as the SDN controller and the OpenFlow is used as the protocol for communication between interfaces. The proposed mechanism will bring many benefits like minimize the errors and save time due to the automated initial configuration in a hybrid-SDN environment, increase efficiency and Performance comparing to the present hybrid-SDN environments.
item: Conference-Abstract
Corridor level traffic management through variable messaging systems: a case study on east west links entering Colombo
(Department of Civil Engineering, University of Moratuwa, 2021-10) Arunakirinathan, V; Premasiri, M; De Silva, D; Matsunuma, T; Perera, HLK
Increasing traffic volumes on the major road corridors result in building up traffic congestion during the peak hours. Even in a congested road network, some route options are relatively lower congested while some are overly congested. This implies that drivers are not always wellinformed about all the route options they have, and the road network is not in a full equilibrium state. When temporary road closures, partial closures for road maintenance, etc. happen chaotic traffic congestion can be seen as drivers try to find alternative routes without proper information about traffic condition in other roads and possible delays. Drivers currently can use vehicle in-built navigational system or smart devices with navigational applications to get real time traffic information. But in a country like Sri Lanka, majority rely on their experiences rather than the digital navigational aid. Displaying the dynamic travel time information and route options using Variable Message Sign (VMS) boards as an adaptive traffic control system, is tested to be simple but highly effective by several researchers. Providing information about the real time congestion level on regular routes and possible delays will help the drivers to avoid the overloaded routes and balance the road network which will ultimately optimize the system performance. One of the key parameters to be considered while implementing an effective VMS system is identifying the locations where the signboards should be erected. These places should be determined considering the route alternatives, possible diversions, and ease of the drivers. This study looks at finding optimal locations to achieve corridor level diversions for the vehicles entering Colombo from east to west direction. The Low-level Road, High-level Road and Kaduwela Road/ Sri Jayawardenapura Mawatha (SJP) corridors are considered the main three corridors from east west direction, connecting the Outer circular expressway and Baseline Road in North-South direction. Among the three corridors SJP is one of the critical corridors where demand exceeds capacity now. A calibrated macro-model covering Western Province of Sri Lanka, was used for the analysis. Select-link-analysis were done to identify the major origin destination pairs of and the route analysis was done separately for each origin links to identify their destination zones and potential diversion volumes. 6 major locations for corridor level diversion using VMS and 7 minor locations to support the major diversion using auxiliary signage boards were identified. From each major diversion locations potential number of vehicles to divert were identified. The results show that with 30% of potential diversion vehicles directed through VMS, a 10% vehicle reduction in Rajagiriya section and 18% in Malabe could be achieved. 19 This method can be adopted to any larger corridor level diversions as well as to local diversions inside the city limits and implemented using movable or fixed VMS with real time traffic information system such as M-TRADA, (A travel time estimator using Google API)
item: Conference-Abstract
Developing a mode choice model using stated preference data for Sri Lanka
(Department of Civil Engineering, University of Moratuwa, 2021) Silva, A; De Silva, D; Perera, HLK
Developing travel behaviour models are important for forecasting travel demand and, consequently, for planning transportation systems. In Sri Lanka, few studies have been done on analyzing mode choice behaviour of individuals. As a result, in most of the studies, transport planners have been struggling to analyze behaviour of people when a new transport mode is introduced or and existing mode is improved. In this study, travel data collected based on a stated preference survey is used to develop a mode choice model. 6834 observations were available for the estimation. Stated preference survey can be used to not only analyze the existing travel modes but also to analyze the new travel modes introduced to a system. The choice of individuals for private modes including, car, three-wheeler, motor bike and public transport including, bus, conventional rail and Light Rail Transit (LRT) modes were analyzed using their attributes. Train mode was further classified on accessibility as bus to train (Bus-Train) and walk to train (Walk- Train). The LRT mode was further classified as walk to LRT, bus to LRT (Bus-LRT), Park and Ride and LRT (PR- LRT). Only the mode attributes and network attributes were used to estimate the user sensitivity. The multinomial nested logit model structure was used where the coefficients of the attributes were estimated using ALOGIT software. The parameters were estimated using number of nesting structures until it reaches a good model fit. It was found that the travel time, distance and cost are significant parameters for all the modes and number of transfers and waiting time are significant parameters in the LRT and Train utility functions. Value of time (VOT) for users of each mode was calculated using coefficients of travel time and cost, an indirect way of estimating the VOT. It was estimated the value of time of users for Car, Motorbike, Three-wheeler, Bus, Train and LRT are Rs.718, Rs.340, Rs.392, Rs.396, Rs.258, and Rs.423 per hour respectively. The estimated mode choice model can be used in the aggregate transport demand models since it is does not have personal attributes of the people who selects the mode. It is identified that importance of inclusion of personal attributes also in a mode choice model. The future studies could include personal attributes and tour attributes which can be used in the activity-based model development. However, the estimated mode choice constants can be calibrated in transport demand modelling to analyse the existing and future travel patterns.
item: Conference-Abstract
Development of a choice model for school trips
(Department of Civil Engineering, University of Moratuwa, 2018-08) Sannasooriya, I; De Silva, D; Pasindu, HR
The school bus service has become more of a necessity due to two major reasons: it engages with the most sensitive crowd in the society, and operates at the most crucial time of the day. A high quality bus service is one of the most important parts of the transportation system as it will reduce the congestion by a large number. Currently it can be clearly seen that many school bus services are not up to the required standard in Sri Lanka with the lack of safety and efficient conditions. Moreover, the dissatisfaction of both parents and their children with the service, has made people switch to the alternative of using the private vehicle to commute to school. Therefore, the transportation industry is in dire need of a high quality school bus service. This study focuses on the attributes of a high quality bus service, compared to the existing transport modes for school trips. Analysis on desired attributes in a high quality school bus service and the model shift from the existing system to the new system, will be stressed. Stated Preference (SP) theory will be the main methodology utilized in the study to find out all the required data. Stated Preference survey or self-stated preference is an efficient method to analyse consumer’s evaluation of multi attributed services, specifically when there are hypothetical choice alternatives and new attributes. In the case of Colombo, Sri Lanka there are no revealed Preferences (RP) data for the high quality school bus service as it is only a Megapolis proposal. Therefore, a Stated Preference survey must be well designed and implemented. There are few objectives defined for this study such as the quantification of sensitivity to the level of service, by varying values of access time, waiting time, travel time and cost etc. to measure the willingness to pay, and to investigate effects of attitudes and perceptions. There are few most probable choice sets to commute to school around Colombo, such as using the private car, school vans and Sisuseriya or other public bus services which have numerous attributes to be considered. Furthermore, the new high quality bus service includes door to door arrivals and drop offs, information services such as Internet, telephone, and GPS navigation, a tracking system and air condition etc. The process of developing the SP survey is categorised in few major steps; I. Defining important attributes II. Designing the questionnaire of SP survey III. Experimental Design IV. Testing the Synthetic Data V. Pilot study and Analysis VI. Revising SP Survey VII. Implementing an Internet survey and supplemental presentable survey When defining important attributes, a focus group discussion will be conducted to collect data. And the questionnaire of the SP Survey will include social-economic information, current travel behaviour, attitudes and perceptions. Model Estimation will be conducted for the travel data. Different model specifications will be compared in this regard. In general, discrete choice models based on a maximum likelihood estimation technique will be used. Further, logit models will be used throughout the analysis. These models capture the influence of attributes and characteristics on the decision makers’ preferences.
item: Conference-Abstract
Development of a personal vehicle type choice model for Sri Lanka
(Department of Civil Engineering, University of Moratuwa, 2018-09) Perera, KR; De Silva, D; Pasindu, HR
Vehicle ownership is a key determination factor in any country’s economy. In the Sri Lankan context, it has been identified that vehicle ownership rate has expressively increased over the last decade. Apparently, the road congestion in urban and suburban areas also have increased significantly. As controlling measures of reducing new vehicle imports, and promoting environmental friendly vehicles, the government has introduced new taxes as well as some increments in the tax level on private passenger vehicles. The overarching object of the research was to examine how a new vehicle choice may vary in the context of household socio – economic characteristics ( eg. income level, number of households, age of the user, gender of the user etc), and the regime of new pricing reforms for annual and variable charging on the vehicle price itself (eg. fuel, insurance and other operational aspects and change of user requirements such as enhancing the vehicle seating capacity, shifting vehicle operating method etc). The respondents participating in the survey, ‘household choice of a new personal vehicle, must have purchased a new vehicle, as the survey is designed accordingly. This paper examines the development of a type of vehicle ownership model using a sample of people living in the Western Province of Sri Lanka. A sample survey is being conducted in the Western Region to collect household data in 2013. ALOGIT software is used to obtain the results of this research. This research considers several potential determinants of vehicle choice, including socio-demographic status. This study primarily attempts to identify how to recognize the family's monthly income, age, occupation, social status, and number of drivers in the family, and their influence on the ownership of the car. The main objective of this research is to help planners and traffic designers to solve the planning and traffic problems in the Western Region. In addition, the result of this research is to assist the Sri Lankan government in imposing the required taxes, and providing as much funding as possible to maximize a sustainable and environmentally friendly transportation system in Sri Lanka.
item: Conference-Abstract
Elderly care home robot using emotion recognition, voice recognition and medicine scheduling
(Information Technology Research Unit, Faculty of Information Technology, University of Moratuwa., 2022-12) Kularatne, BMUS; Basnayake, BMJN; Sathmini, PDLAM; Sewwandi, GVU; Rajapaksha, S; De Silva, D; Sumathipala, KASN; Ganegoda, GU; Piyathilake, ITS; Manawadu, IN
The robotic concept is used for several tasks to easier human day-to-day tasks. There are various recreational studies have been done on the elderly people’s care system. In this study, the system can identify the elderly people’s emotional status using thermal image processing that eliminates the halo effect issue in thermal images using a single discriminator Cycle-GAN model, serving medicine to elderly people by moving towards the elderly person while avoiding obstacles using point to point algorithm and obstacle avoidance and identify the semantic analysis by using web ontology based language. The integrated system is evaluated using the Gazebo simulator because the cost is lower than implementing the features in a real robot.
item: Conference-Abstract
Elderly care home robot using emotion recognition, voice recognition and medicine scheduling
(Information Technology Research Unit, Faculty of Information Technology, University of Moratuwa., 2022-12) Kularatne, BMUS; Basnayake, BMJN; Sathmini, PDLAM; Sewwandi, GVU; Rajapaksha, S; De Silva, D; Sumathipala, KASN; Ganegoda, GU; Piyathilake, ITS; Manawadu, IN
The robotic concept is used for several tasks to easier human day-to-day tasks. There are various recreational studies have been done on the elderly people’s care system. In this study, the system can identify the elderly people’s emotional status using thermal image processing that eliminates the halo effect issue in thermal images using a single discriminator Cycle-GAN model, serving medicine to elderly people by moving towards the elderly person while avoiding obstacles using point to point algorithm and obstacle avoidance and identify the semantic analysis by using web ontology based language. The integrated system is evaluated using the Gazebo simulator because the cost is lower than implementing the features in a real robot.
item: Conference-Abstract
Evaluation of commercial land price change in response to transport infrastructure improvement: a case study on proposed LRT line in Sri Lanka
(Department of Civil Engineering, University of Moratuwa, 2021-10) Iqbal, S; De Silva, D; Perera, HLK
Transportation and Land Use are part of a wider activity system where the interaction between them is part of a complex framework. While the changes in Land Use characteristics would lead to change in activity patterns influencing the Transportation System, the changes in the Transportation Infrastructure have a direct impact on the change in overall accessibility levels as well as the relative accessibility of the specific locations. Thus, it is expected that any change in Transportation Infrastructure would lead to change in Land Use demand reflected with the changes in land prices. This research is targeted to capture the impact of Transport Infrastructure on Commercial Land prices. The proposed Colombo Light Rail Transit (CLRT-JICA) project has been selected as a case study to obtain the sensitivity of the Commercial Land prices under 3 stages, Pre-Introduction (2010-2014), Planning/Designing phase (2015-2019) and the Construction stage (2020-2021). Although the project was suspended in the year 2020, the research was extended beyond 2020 to observe the impact it has on Commercial Land prices which increased solely due to the CLRT. The Commercial Land price data obtained from two of the most prominent online web advertising agents, “Lanka Property Web” and “ikman.lk”, within a 2 km radius of four proposed main stations; Malabe, Battaramulla, Rajagiriya and Borella have been used in the evaluation. Narahenpita area (with an existing Railway Station) has been selected as the base to consider the prevailing trend of Commercial Land prices. A Multiple Regression Analysis using SPSS was carried out to find the relationship between the Commercial Land price per unit area as the Dependent Variable, explained by several Independent Variables such as the Distance to the nearest station, Distance to the main road, features of the property such as parking availability. The analysis is expected to explain how the price of Commercial Land is expected to have different sensitivity based on the independent attributes and the variation based on the stage of the Transport Infrastructure Project.
item: Conference-Abstract
Evaluation of impact of access roads on traffic flow on arterial roads in Colombo
(Department of Civil Engineering, University of Moratuwa, 2021-10) Mudalige, MH; De Silva, D; Perera, HLK
The rapid development of Colombo city has resulted in growth in urban traffic. The arterial roads that provide accessibility to Colombo city are experiencing traffic congestions, especially during peak times. The vehicles that enter these arterial roads through closely spaced access roads and exiting vehicles to access roads from the arterial, can be considered as a major contributor to causing traffic congestion. This paper analyses how the close-distance access roads affect the traffic flow on arterial roads. A virtual scenario for a 1km multi-lane arterial road section with separated two lanes in one direction and access roads were connected from the both sides of the arterial road, was created in VISSIM software based on a case study of Galle-Colombo arterial road to replicate local conditions. The flow rate on the arterial road was varied to understand the total delay of the network system and the flow rate of the major arterial roads with varying access road distances. Furthermore, identify the combined impact that can occur within the road network was evaluated by defining an index. The index was defined by considering the total delay of the network system and the flow rates of the major arterials. The recommended distance between access roads to arterial roads was identified as a part of the study. It is recommended that access roads may connect with a minimum of 250m-275m distance between their center lines in a 1km arterial road section for 1000veh/hr to 4000veh/hr volume of arterial flow. One of the findings of this study was when future planners designing urban road network systems, access roads should be connected in above mentioned distance range between their center lines, regardless of the vehicle volume of arterial roads, to minimize total delay of the road network and maximize the through vehicle flow of arterial roads.
item: Conference-Abstract
Factors which influence non-recreational cycle use in the urban context of Sri Lanka
(Department of Civil Engineering, University of Moratuwa, 2022-12) Geeganage, C; De Silva, D; Perera, HLK
Non-recreational cycling has been promoted for Colombo and other urban areas in Sri Lanka mainly through promotional campaigns and the provision of cycling infrastructures such as bicycle lanes or paths. However, there are no studies on real factors which influence the non-recreational cycling behaviour in the Sri Lankan context, suggesting that most of these infrastructure developments are not supported by studies. Information on non-recreational cyclists' preferences and behaviour is important for the effective planning of cycling infrastructure. This paper presents the findings to identify the most relevant factors which influence non-recreational cycling behaviour in the urban context of Sri Lanka. The factors which influence non-recreational cycling behaviour were initially captured through a comprehensive literature survey, and following that, the most influential cycling infrastructure-related factors as applicable to Sri Lankan urban context were identified through an online questionnaire survey. About 60 influential factors were identified in the literature, and among these, 16 cycling infrastructure-related factors, which were assumed to be applicable to a context where cycling is in the promotional stage, were selected to include in the questionnaire survey in the form of ranking questions. The questionnaire survey covered a sample of 400 online respondents, including 15% of existing non-recreational cyclists and 33% of existing recreational cyclists. The sample consisted of 61% of female respondents and 63% of respondents belonging to the age category of 26-35 years and 14% the 36-45 years. 79% of respondents were full-time employed either in the public or private sector. 44% of respondents use a car, van or jeep as the main mode of transport, while 32% use public transport. The selected 16 influential factors were divided into four categories, and the respondents were supposed to rank the set of factors in each category and finally assign the ranking for the four categories separately. Results revealed that the 'type of road facility is the most important category of influential factors, followed by 'safety attributes', 'supportive cycling facilities' and 'characteristics of cycling facilities. Among the four types of road facilities, 'riding on a dedicated bicycle pathway free of pedestrians or any other traffic' was the most preferred having 61% of respondents ranking it as their 1st choice and 'riding in mixed traffic' was the least preferred having 82%of respondents ranked it as their 4th choice. 2nd and 3rd ranked were 'riding on a demarcated bicycle lane on the road' and 'riding on a bicycle pathway shared with pedestrians' respectively. Among the three safety attributes, 'having a smooth, non-slippery riding surface' was ranked 1st, followed by 'having adequate lighting on bicycle pathways during night-time' and 'having overpasses to avoid complex intersections'. Among the six attributes under the 'cycling supportive facilities' category, 'availability of secured parking facilities at destinations' ranked 1st, followed by; 'availability of relaxing areas with basic facilities, 'availability of bicycle-friendly public transport', 'availability of locker facilities at the destinations', 'availability of a bicycle renting and sharing system' and 'availability of showers and changing facilities at destinations. The remaining six attributes under the 'characteristics of cycling facilities' had been ranked in the order of; 'having adequate shade and trees' as 1st followed by 'direct connection to the target destinations via shortest paths', 'the route having direct connections to multiple uses like banks, shopping and schools etc.', 'having a continuous route without gaps in between, 'the route to ply along pleasant scenic views' and 'high security guaranteed with CCTV monitoring' as 6th.In the overall ranking of attributes regardless of the category of influential factors, 'having a smooth, non-slippery riding surface' was ranked 1st, having a relative score of 11.3% and factors such as 'adequate lighting' (9.2%), 'having overpasses' (7.7%), 'secured parking facilities (5.0%), 'adequate shade and trees' (4.2%) and 'direct connection to the target destinations via shortest paths' (4.0%) were among the first top ten ranked influential factors along with the four types of road facilities for cycling. However, respondents had given relatively less priority in their preference for attributes such as 'availability of relaxing areas with basic facilities (3.8%), 'bicycle-friendly public transport' (3.5%), 'route having direct connections to multiple uses such as banks, shopping and schools etc.' (3.3%), 'bicycle renting and sharing system' (3.1%), 'locker facilities' (3.1%), 'showers and changing facilities at destinations' (3.0%), 'having a continuous route without gaps in between (3.0%), 'having pleasant scenic views' (3.0%) and 'high security guaranteed with CCTV monitoring' (2.3%), although most of these are perceived as important factors in similar studies conducted in contexts where non-recreational cycling is a more frequent mode of transport. The reason why some of the factors, such as availability of lockers, showers, changing facilities, direct connections, relaxing areas with basic facilities, bicycle-friendly public transport and bicycle renting and sharing systems which are highly demanded in other bicycle-friendly cities, had been given less importance by the respondents could be because they are not existing cyclists and that they may find it important once they start non-recreational cycling. The future works of this study include a stated preference survey and analyzing stated preference observations with logit choice estimations in order to identify the relative importance of identified most relevant influential factors.
item: Conference-Abstract
Identification of attributes influencing a functional park and ride systems for colombo
(Department of Civil Engineering, University of Moratuwa, 2022-12) Samarasekara, K; De Silva, D; Perera, HLK
Colombo, being the commercial capital and largest city of Sri Lanka by population, is plagued with traffic congestion in most of the corridors. Improving public transportation has been identified as the foremost approach to solving the congestion considering private vehicles have a higher share of the vehicle composition and carry fewer amount of passengers. Authorities have come up with different solutions like providing flyovers, constructing bypass roads, introducing bus lanes, increasing taxes on private vehicles, and widening existing roads, yet an intact result has not been delivered to Colombo city. 'Park and Ride' has been identified as one of the functionalities to make public transport more attractive because it aims to influence travellers' attitudes and behaviour into shifting from private vehicle use to mix mode of transport. A questionnaire survey was carried out to understand the attributes that influence the choice of passengers to use the Park and Ride system. The set of attributes listed in the questionnaire was obtained from previous studies conducted in different regions under different conditions. Selected attributes were categorized in to 6 major categories as; 'parking facilities' which asks respondents to rank a list of characteristics related to the car park in a park and ride system, 'facilities and services provided at the park and ride station' which asks respondents to rank a list of characteristics related to the park and ride station, 'characteristics and facilities provided in public transportation mode', which asks respondents to rank a list of characteristics related to the mode of public transportation (i.e. train, bus LRT), 'travel time characteristics' where respondents find a list of different time components related to a park and ride system (i.e. time spent on public transportation, time spent walking to the destination), 'availability of public transport mode', which asks respondents preference regarding the availability of different combinations of public transportation modes (i.e. availability of bus only, availability of LRT and bus only, availability of bus, rail and LRT) and 'general characteristics of park and ride', where respondents find a list of attributes which does not lies under any of the previous categories. 5-10 attributes were listed under each category, and respondents were asked to rank the given list within the category based on their preference. Each attribute was given a score referring to the survey results. The number of respondents who have ranked a certain attribute as '1' is counted, and it was multiplied by a relatively higher number (multiplying factor) based on the number of attributes given under that category. The same procedure was followed to allocate scores for the rest of the ranks (2,3,4.) given for that certain attribute, and the multiplying factor was reduced when the rank reduces. Sum of the scores for ranking as '1', ranking as '2' and the rest is taken as the score for that attribute, and a score was given to all the attributes by following the above method. Further, as the last stage of this survey, respondents were asked to rank the given major categories based on their perspective. The same mathematical analysis method used for ranking the attributes within the category was followed to allocate a score for the categories also. A final score was obtained based on the 'scores given for attributes within the categories and the 'scores given for the categories itself. This leads to the identification of 40 the most prioritized attributes regardless of major category. Using the above set of prioritized attributes, a stated preference (SP) survey can be conducted with a sample size of around 400 to identify the user perception of the attributes. The initial survey was conducted to identify the most important characteristics from the long list of characteristics obtained from the literature, and the highest-ranked attributes of that initial survey can be used for the SP survey. 380 responses were obtained for the aforementioned initial survey, and the results of the questionnaire revealed that 'certain seating facility in the public transportation mode', 'availability of the washrooms at the station', 'secure parking at the station', 'time spent waiting in park and ride station' and 'displaying Information on services (bus route/time, etc.) in the station' were the highest ranked attributes. It also exposed that respondents have less concern about 'having free parking at the station' and 'having a low cost or public transportation. Moreover, the results showed that the respondents prefer to have more options as their public transportation mode instead of having a single mode. This ranking of attributes generates a clear view of approaching the planning and design stages of public transport projects by providing scientific evidence so that ad-hoc decisions will be avoided. Therefore, the findings of the study would provide useful insights into the feasibility assessment of public transport projects, especially in the Colombo region.
item: Conference-Abstract
Identification of attributes on selection of a departure airport in Sri Lanka
(Department of Civil Engineering, University of Moratuwa, 2022-12) Daluwatta, O; De Silva, D; Perera, HLK
The world has become a smaller place through the expansion of the aviation industry. Commercial airports enable millions of people to travel for business, go home for the holidays, take vacations around the globe, or travel to other important events. Most contemporary airport management studies and research focus on airport efficiency, effectiveness, processing speed, and ranks on international league tables. These policies appear to favour airports that can efficiently transport most travellers and their luggage. Identification of passenger airport choice determinants may be of great value to airport managers as it can assist with determining passengers' demand at the Airport. These studies include different airports and different segmentations of passengers. Air passengers usually choose airports after considering multiple factors such as airfare, frequency of flights or flight schedule, access time, airport delay, and modes of the Airport. The choice may be influenced by the socio-economic characteristics of the individuals and the purpose of the travel. However, there is no general approach to model how air passengers will choose their origin airport in response to attributes of the air travel, attributes of inside and outside the terminal based on their travel purpose. It is important to identify the attributes that will influence a departure passenger to select a departure airport because it is a crucial component when planning passenger redistribution policies. This paper adds to the body of knowledge by providing a deeper understanding of the variables affecting air traveller's experience as expressed by travellers depending on their trip purpose, whether it is business, leisure, pilgrimage or migrant worker trip. The objective of this paper is to identify the influential factors for selecting a departure airport by air travellers based on their travel purpose, which is fulfilled based on the data collected from air travellers who visited Bandaranaike and Mattala International Airports. For this purpose, 350 individuals were sampled using a special questionnaire through internet-based and direct personal interviews. The analysis presented in this paper has shown the important role of Air Ticket Price, The Access Time to the Airport, The Number of Transfers to the Destination and The Number of Flights per Day to the Destination were found to have a consistently significant effect on Business, Leisure and Migrant travellers while Air Ticket Price, The Cost of Getting to the Airport, The Number of Flights per Day to the Destination and Availability of multiple transport modes to the Airport were significant for Pilgrimage travellers in airport selection. As a further study, the selected attributes will be used on the SP survey to estimate a logit choice model for the selection of a departure airport. The findings of the research can be used by the airport authority and various transport operators for evaluating the changes in the service attributes in international airports improving the discounted airfares, ground access mode services, airport facilities, and airport efficiency for increasing the competitiveness of the Airport.
item: Conference-Full-text
Methodology of developing a tour mode choice model of workers in western province, Sri Lanka
(IEEE, 2022-07) Pathirana, DK; Sirisoma, N; De Silva, D; Rathnayake, M; Adhikariwatte, V; Hemachandra, K
This study is based on work tours which can identify by considering all the trips as a chain starting and ending at home. Tour mode estimation is one step in the Activity-Based Model needed to be followed once tour patterns are identified. The socio-economics/demographic characteristics of individuals and households, level of service attributes, tour/trip details, and land-use attributes influence tour mode. A choice model needs to estimate the tour mode using these influential factors. Assigning a tour mode for each tour is required before model formulation. The main objective of this paper is to propose a method to estimate tour modes for individuals in Western Province, Sri Lanka. The required travel details were collected from the CoMTrans 2013/14 Household Visit Survey data. This paper includes only the work tours and describes the methodology to estimate the tour mode choice model. The authors introduce a process to identify the tour modes out of trip modes. The descriptive analysis of tour mode with the tour pattern details is included. The estimated results in tour mode for the Colombo district were presented. The mathematical techniques, details of data needed, and required software for estimating the tour mode choice model are mentioned in this paper.
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Minority resampling boosted unsupervised learning with hyperdimensional computing for threat detection at the edge of internet of things
(Institute of Electrical and Electronics Engineers, 2021) Christopher, V; Aathman, T; Mahendrakumaran, K; Nawaratne, R; De Silva, D; Nanayakkara, V; Alahakoon, D
The Internet of Things (IoT) has rapidly transformed digital environments across a multitude of domains with increased connectivity and pervasive virtualization. The distributed computing paradigm of Edge Computing has been postulated to overcome the concerns of response time, bandwidth, energy consumption, and cybersecurity. In comparison to the other concerns, limited studies have focused on cybersecurity, mainly due to the inherent complexity of threat detection at the Edge. However, the widespread adoption of IoT applications in economic, social, and political contexts is a stringent indication of the signi cant impact from cyber-attacks. This paper aims to address this challenge by presenting an effective and ef cient machine learning approach for threat detection at the Edge of IoT. The novel contributions of this approach are, a new Enhanced Geometric Synthetic Minority Oversampling Technique (EG-SMOTE) algorithm to resolve the imbalanced distribution of data streams at the IoT Edge, an extension to the Growing Self Organizing Map (GSOM) algorithm based on Hyperdimensional Computing for energy ef cient machine learning from unlabeled data streams. The proposed EG-SMOTE C GSOM approach has been tested using four open access datasets; three benchmark, KDD99 (F-ScoreD0.9360), NSL-KDD (F-ScoreD 0.9647), CICIDS2017 (F-Score D 0.9999), and one industry-focused botnet IoT traf c dataset, BoT-IoT (F-Score D 0.9445). The EG-SMOTE approach has outperformed SMOTE and G-SMOTE approaches in a vast number of experiments that are tried with different classi ers. The results of these experiments con rm the novelty, ef ciency and effectiveness of this approach for cybersecurity at the IoT Edge.
item: Conference-Abstract
Potential of applying Built-Operate Transfer (BOT) system for Sri Lankan highways- case study on Colombo-Katunayaka Expressway (CKE)
(Department of Civil Engineering, University of Moratuwa., 2018-08) Perera, MAP; De Silva, D; Pasindu, HR
The Sri Lankan transport network had a massive development during the last decade, experiencing highway infrastructure with the utilization of foreign concessions and local government funds of the country. The Road Development Authority holds the pioneer authority to operate and maintain the system periodically. The user benefits generated with these highways include travel time saving, developed infrastructure and living standards, also social benefits which are not counter measured quantitatively. As a developing country, the lack of financial stability for infrastructure of the government may lead to foreign loans and concessions. The concessions lead to rapid involvement in the fund involvement for mega infrastructure projects as the necessity and demand of the country. The Build - Operate and Transfer (BOT) concession model is becoming a major trend in the privatization of the infrastructure projects, the concession period and interest rate are the critical parameters for BOT contracts. A model for the evaluation of the potential of applying BOT system for the highways is developed in the study. The demand estimation, operation and maintenance cost, and toll income are used as the inputs for this model and financial viability is observed with different scenarios. The concession period, interest rates and optimality of the selection of BOT are decided with different criterions based on financial viability. As the Colombo-Katunayake Expressway (CKE), meets the highest demand for traffic in the Sri Lankan highway network, it is used to demonstrate the applicability of the proposed methodology. To minimize the ridership guarantee, the gap in-between the accumulated revenue and accumulated costs, optimum subsidy level is eliminated by differentiating acceptable criterions. Also, the BOT model is further expanded with risk assessment with the current trends, applying the suitability of applying to the expected income gain interconnecting with the Outer circular highway (OCH), Southern Expressway and ongoing Central Expressway to the CKE with different scenario analysis by minimizing the ridership guarantee.
item: Conference-Full-text
Reducing container inventory management cost: the smart use of Internet of Things (IoT)
(Sri Lanka Society of Transport and Logistics, 2021-10) Edirisinghe, H; De Silva, D; Gunaruwan, TL
Since shipping derives its demand from international trading, the quantity of containers imported and exported to a country rarely match. As a result, shipping lines (SL) incur an additional cost: namely, the empty container reposition cost. This refers to either the export of excess containers to another country where they are needed or import of empty containers from a port where they are in abundance. Given that Internet of things (IoT) is gaining momentum, this paper proposes a method to enhance the effectiveness and efficiency of container inventory management (CIM) using IoT. The specific CIM tool to which the paper refers is the virtual container yard (VCY): an online tool that follows the fundamentals of collaboration between L). It operates through an algorithm to exchange containers between SLs. The paper examines the process of the VCY and ascertain how IoT could improve its ability to reduce CIM cost while improving service quality. It is identified that IoT could play a key role in identifying potential SLs for exchange, in determining the quantity of containers based on type, size, and other factors, and in exploring port pair option for the most economical exchange.
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The Study of brightness levels of headlights of operating vehicles in Sri Lanka
Senarathna, RMSK; De Silva, D; Perera, L
Driving an automobile is primarily a visual task, and vision contributes as much as 90% of the information required to drive (Alexander and Lunenfeld 1990). At night time, the required visibility level of roadway is created artificially by vehicle headlights or street lighting or both. Illuminating roadway using vehicle headlight is the most common method at night time driving, but too much light and improper lighting may result in glare, which causes visual discomfort and a diminished ability to see the roadway. In another way, insufficient light causes problems for drivers to see the information needed or potential hazards in the roadway. There are many different kinds of headlight systems in operating vehicles (imported from various manufactures of various countries in various time periods) in Sri Lankan roads including the oldest systems and the most upgraded systems. Generally, a halogen headlamp system which is commonly found in Sri Lankan roads is expected to be performed well for about 10 years in normal conditions. But the percentage of older vehicles more than 10 years is higher in Sri Lankan roads. Different organizations all around the world have introduced regulations on vehicle headlights not only for the vehicle manufactures but also for the drivers. Comparisons show that the current Sri Lankan regulations have not been updated to address the issues. Even though the road surfaces have been improved so that encouraging drivers to drive faster, other factors have not been considerably improved. Therefore, introducing of the new regulatory system should be considered to control this vast variety and mitigate the risk and un-comforting condition. The intention of this research is to identify brightness levels of operating vehicles in Sri Lankan roads based on Federal Motor Vehicle (USA) regulations which may helpful in above discomfort circumstances. The experimental brightness levels of headlights were measured by simulating the testing arrangement at a work station free for night time. The readings were taken in terms of ―Lux‖ and maximum and minimum levels of brightness were identified. iv The results of field tests revealed that the majority of operating vehicles has less brightness levels compared with the minimum brightness level specified in the Federal Motor Vehicle Regulation. Vehicles older than five years were failing to produce a sufficient intensity for low beam operation compared to the FMVSS limitation. Further, it was revealed that the most headlights of operating vehicles are miss-aimed and illuminate unnecessary regions which cause inconvenience to the drivers of oncoming vehicles. Also, it was revealed that the driver’s attention to the maintenance of the headlight system of their own vehicle is very poor. Finally, this research suggests introducing regulations to minimize or mitigate adverse effects of headlights by periodically evaluating headlight systems of operating vehicles based on a proper regulator system in Sri Lanka.