Browsing by Author "De Silva, GLDI"

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item: SRC-Report
An Activity allocation model for Sri Lanka using PECAS framework
(2016) De Silva, GLDI
Traditional Transport Models can under or overestimate the benefits when they try to model a rapidly changing economic surrounding. While looking into transport aspects, they cannot account the changes., the transportation causes on other systems, which ultimately act upon transportation itself. Even though the land use transport integration is a complex process to model, PECAS (Production, Exchange, Consumption Allocation System), a generalized theoretical framework for representing spatial economic systems, is capable of modelling the integrated nature of land use and transportation efficiently due to its intrinsic capabilities of modelling all economic subsystems with acceptable accuracy levels. While the use of PECAS is widely tested in developed countries, only a limited number of studies have been carried out in developing countries. Thus, the study focused on developing one of the major components of the framework, an Activity Allocation Module. First, study checked the possibility of adopting the PECAS framework for Sri Lanka, identified data to be derived and did necessary processing. Data gathered from national accounts of Sri Lanka, input output tables, supply and use tables, other surveys conducted by Department of Census and Statistics and data from other sources were assessed, to check the suitability of available data to prepare economic and land use inputs to the model. Development of key elements of an Activity Allocation Model were completed with available and synthesized data. As the basic output of the study, an Aggregate Economic Flow Table was developed with 42 commodity categories (17 good categories, 11 service commodities, 11 labour categories, 3 space categories and 8 financial and adjusting categories), 12 manufacturing activities and 11 service activities. It includes government and 3 categories of households. Import and export markets are also accounted.
item: Conference-Full-text
Activity Participation Patterns of Individuals in Sri Lanka
(IEEE, 2021-07) Malshan, TMP; De Silva, GLDI; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
Activity-based models are replacing commonly used traditional four-step models due to their high temporal and spatial resolution, integrity, interdependency, and behavioural basis. The foundation of an activity-based model is the activity participation pattern of an individual in the study area considered. This paper uses the time use survey data, collected by the Department of Census and Statistics and analyses them as the first step of building an activity-based model for Sri Lanka. Variations on weekday and weekend activity patterns were analysed separately. Since they are considerably different, the focus was on weekday activity participation patterns. The differences in activity participation patterns across gender, age, and geographical location were identified which are useful when building an activity-based model for Sri Lanka.
item: Conference-Full-text
Analyzing the geographical catchment areas of fort-malabe lrt by access modes
(IEEE, 2020-07) Mendis, BHA; De Silva, GLDI; Weeraddana, C; Edussooriya, CUS; Abeysooriya, RP
Development of transport sector is a timely need for a developing country such as Sri Lanka. Especially the public transport sector. Mass transit systems serve as the backbone transport systems while feeder modes enable the connections between the origins and mass transit connection points. Currently passengers use private feeders and non-private modes. A proper feeder network is vital for the success of a mass transit network. In this paper, Fort- Malabe LRT which is the newest mass transit that is being introduced to Sri Lanka, is analyzed. Spatial extents of catchment areas for access modes were taken using survey data for each feeder mode. The station wise catchment distances and corridor wise catchment distance for each mode is discussed and compared. There are two approaches utilized in identifying the geographical buffer area. In the first approach, circular buffer, the area that is contained by the Euclidean catchment distance is taken. In service area approach the catchment by road network is taken. The geographical catchment areas for different access modes were concluded, for each mode of feeder, using Geographical Information Systems (GIS) and solutions that can be applied for maximizing the catchment areas were suggested using Conveyal analysis.
item: Conference-Abstract
Delay analysis at a signalized T intersection
(2017) Vajeeran, A; De Silva, GLDI
Traffic signal delay is one of the major problem people face in urban areas. An effective traffic signal timing and phasing arrangement has to be implemented to optimize the delay for all vehicle moments through the junction. Apart from signal timing arrangement, other factors such as geometry also influence the delay at an intersection. The aim of the research is to analyze and find the parameters influencing the delay at a signalized intersection and get an optimize condition which can reduce the delay at the selected junction. For the case study Katubedda Junction has been selected. The traffic simulation software vissim has been used for the analysis. Calibration of the vissim model to Sri Lankan conditions was achieved by changing the driving behavior parameters of the software model and matching the propagated queue length in model with actual queue length. Some of the causes of the delay were identified and those geometrical and signal timing changes were categorized into three different alternatives. All three alternatives were modeled in the software with the existing condition as the base case. The results show that changes in signal timing arrangement and changes in the geometrical arrangement has to be done to reduce the delay at the selected location.
item: Conference-Abstract
Delay analysis at a signalized T intersection using VISSIM software
(Department of Civil Engineering, University of Moratuwa., 2016-08) Vajeeran, A; De Silva, GLDI; Pasindu, HR
Traffic signal delay is one of the major problem people face in urban areas. Though the traffic signals sometimes create a delay itself, they are needed for the safety of the junction to prevent collision between several vehicle movements. Delay is a component related with time which is more precious. A proper traffic signal arrangement has to be implemented which can optimize the delay for all vehicle moments through the junction. Apart from signal timing arrangement, other factors such as geometry also influence the delay at an intersection, which should be considered when analyzing the delay. The aim of the research is to analyze and find the parameters influencing the delay at a signalized intersection and get an optimize condition which can reduce the delay. Katubedda Junctions which is a T intersection has been selected for the case study. The traffic simulation software VISSIM has been used for the analysis. The geometrical arrangement, signal timing and traffic flow data was collected through a video survey. Driving behavior parameters is the key to calibrate the software model to Sri Lankan conditions. This was achieved by changing the driving behavior parameters of the model and matching the propagated queue length in model with actual queue length. Some geometrical and signal timing changes were categorized into three different alternatives which were modeled in VISSIM with the existing condition as the base case. The results show that changes in signal timing arrangement and changes in the geometrical arrangement has to be done to reduce the delay at the selected location
item: Conference-Abstract
Developing a PECAS spatial economic model for Sri Lanka: opportunities and challenges
(Department of Civil Engineering, University of Moratuwa., 2016-08) Premasiri, SMPM; De Silva, GLDI; Pasindu, HR
With the fast-growing economy of Sri Lanka, many new economic activities are taking place. These economic activities have direct impacts on changing, adjusting or reshaping the current land use patterns. (residential, commercial, industrial, institutional, mixed, etc.). Apart from that, the government policies on planned developments; namely the expressways, airports, ports, new LRTs (Light Rapid Transit), new railway lines, etc. have clear impacts on the current use of the land. Even though these are very complex processes to model, a PECAS (Production, Exchange, Consumption Allocation System) special economic model is capable of modelling very slow (networks/land use), slow (workplace/ housing), fast (employment/population) and immediate (goods transport/travel) economic activities on an urban subsystem with an acceptable accuracy, providing a scientific way of predicting land use changes. Thus, a carefully calibrated PECAS spatial model can be used for evaluating and forecasting of land use patterns due to policy changes or infrastructure developments. This will be highly beneficial to infrastructure planners, economists, policy makers, investors and especially transport planners, because the differences in land use are the basic origins of transport needs. Thus, there are numerous opportunities to develop a PECAS spatial model for Sri Lanka, while the acceptance of the need for integrated land use and transport planning for Western Region Megapolis Planning Project (WRMPP), a multi-billion, flagship project implemented by the Sri Lankan government, being the most important one. Main challenges of developing a PECAS model for Sri Lanka arise with inefficient, incomplete or unavailable data. Social Accounting Matrices (SAM) are considered to be the friendliest data source while developing a PECAS model. An effort has been taken on developing a framework for developing SAMs for Sri Lanka but a complete SAM is not present yet. The next best data source is Input-Output tables (I/O tables). They have been developed only for 2001 and 2006 in recent past. Among those two also 2001 tables are considered a failure and anyhow it is quite outdated for today. The one developed for 2006 by Asian Development Bank (ADB) consists 24 activity categories and 34 commodity categories, but only one household category and labour category. Apart from above data, available other data sources on space data (especially the distribution of non-residential space) and labour data (employment and income) are also not up to the expected level and descriptiveness. Problems like inefficiencies, inconsistencies, interpretation problems and data not being in readable formats can also be seen in available data. The complexity and the usefulness of a PECAS model increase from Setup Model through Demonstration Model to Production Model. As Demonstration Models and Production Models are more data hungry, previous studies show that acquiring data for developing such a model will be quite expensive (more than Rs. 100 million). Allocation of such an amount of money just for a planning process is still a challenge for Sri Lanka. Therefore, it can be concluded that developing a PECAS spatial economic Setup Model is the most viable one for the time being.
item: Conference-Full-text
Development of a cell transmission model using crowdsourced data for expressways
(IEEE, 2021-07) Wijepala, WMRV; De Silva, GLDI; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
The demand for expressways in Sri Lanka is rapidly increasing with the increasing traffic congestion in alternate roads. Traffic management strategies have to be considered with further increase in demand 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 a Cell Transmission Model using crowdsourced traffic data collected by Google Distance Matrix API. An expressway section was selected and divided into number of cells. The average speed of each cell was collected from Google maps using the M-TRADA platform for every 5-minutes interval. The speed data collected were represented in a spatiotemporal graph. The cell lengths were varied to identify the optimum cell lengths for the model. It was found that the vehicle flow in the selected section is significantly lower than the capacity of the expressway. Therefore, significant speed drops are not frequent. This model is more useful for expressways when it's at higher demand. A user interface is proposed for a web application that can be developed using this model for real-time traffic monitoring purposes, which even non-expert users will be able to because of the simplicity.
item: Conference-Abstract
Development of general transit feed specification data for Sri Lanka
(Department of Civil Engineering, University of Moratuwa., 2019-09) Fernando, PDL; Mendis, BHA; Damsara, KDP; Kumarage, SP; De Silva, GLDI; Pasindu, HR
General Transit Feed Specification (GTFS) refers to a common format that is used to represent transit data such as schedules and related geographical data (i.e. transit routes, stops). Provision of a specification for presenting transit data has expanded its applicability ranging from trip planning applications to operation analysis and research. At present transit data in Sri Lanka can be publicly accessed through each agency’s website or through applications developed based on these data. The interconnectivity of transit data of different transit agencies is absent at present and the development of GTFS data will address the issue. A GTFS feed generally contains agency, routes, trips, calendar, stops, stop times, shapes, frequencies and transfer files. The Paper addresses aspects considered for the development of frequencies, stop times and transfers files in Sri Lankan context. Frequencies can be represented in two ways based on the availability of a fixed schedule throughout the day by using the “exact_time” field. The paper highlights how the “exact_time” field was used for some bus routes of low frequencies. Development of stop times file is based on each transit mode’s timetable. But for buses, the data relating to stop time at each bus stop is not available. The paper highlights how these values were derived for Western Province Transport Authority (WPTA) buses and the National Transport Commission (NTC) buses based on average travel speed while maintaining priority for trips within the Western Province to WPTA buses. The transfer file enables transfers from buses to trains or vice versa. Due to the dispersed locations of railway stations and bus stops in some parts of the country and the number of data to be found being high an efficient way is suggested in the paper using the network analyst tool in ArcGIS software.
item: Conference-Abstract
Development of stop times file for general transit feed specification (GTFS) format in the context of Western Province bus transits
(Department of Civil Engineering, University of Moratuwa., 2019-09) Mendis, BHA; De Silva, GLDI; Pasindu, HR
Public transport which is a vital aspect of transportation consists of a modal share 40.4% in Western Province of which 37.7% is of buses. However, regarding the convenience and ease of access to information, not so many measures are implemented in Sri Lanka. Recently in order to communicate better service information on public transportation to users, Google Transit service was enabled in Google Maps. To provide the information via Google Maps, Google accepts the data feed in the format of General Transit Feed Specification (GTFS) which is an international data format. Currently a static feed is provided which includes the components of schedule, fare and geographic transit information. The schedule component contains the file stop_times.txt which provide the schedule of a bus journey. For a certain bus journey, it gives the stops that the riders board and alight, arrival and departure time at each stop and the stop sequence of a certain journey. However, in Sri Lankan context, the transport agencies use the fare tables (figure 1) which depicts the stops that the bus makes and the fare at each stop and the bus frequency (figure 2) which gives the times that a bus of a certain route would leave the initiating bus station. In coding the arrival and departure times at each bus stop is required. However, in Sri Lanka no such time table exist for each and every bus stop. Therefore, an average speed was identified for each route and considering the distance travelled, arrival and departure times were recorded for each stop in a bus journey. In obtaining the average speeds, for the inter provincial buses, the average speed in the annual report of National Transport Commission was referred. In order to get the Western Province intra provincial bus average speeds the speed graphs of the CoMTrans Study were referred. An average speed for the whole day was taken approximately for all inter-Provincial buses. In practical scenario, inside Western Province most inter provincial buses do not allow the riders riding for a short distance to board the bus. Instead they are required to take the intra provincial bus. However, as the inter provincial buses travel faster than the intra provincial buses within the Western Province too, the google will indicate the inter provincial bus as the preferred best route. User is misguided. Another error identified in inter-provincial bus routes is, bus routes in the same corridor having different average speeds. For an example the two buses Colombo-Kandy and Colombo-Katugasthota travels in the same corridor. But the Colombo-Katugasthota bus route’s allocated average speed is higher than the Colombo-Kandy bus route’s average speed which are defined by NTC. Therefore, higher speeded bus route is given priority which is misleading. For above errors mitigation methods were carried out by adjusting the speed of bus routes depending on the practical scenarios, traffic conditions, Western Province boundaries and the impacts of expressway network. Also, a major drawback of coding exact times for bus routes is that is not representing situations where the buses being delayed or cancelled. Also the waiting time at each bus stop varies and cannot be reasonably included in the coding. In order to represent the most accurate service information, the real time data feed is required.
item: Conference-Full-text
Effectiveness of manual control of traffic signals during peak hours
(IEEE, 2022-07) Vajeeran, A; De Silva, GLDI; Rathnayake, M; Adhikariwatte, V; Hemachandra, K
One of the major reasons for congestion is ineffective control at intersections. During the peak hours there has been observed that many signalized intersections in city centers are controlled manually by police officers either by switching off the signal lights or by flashing amber. The objective of the study is to find the effectiveness of manual control compared to traffic signals. Four Junctions which are controlled manually during the peak hours were selected and modelled for three cases, existing posted signal time, updated traffic signal time, and traffic police phase arrangement and cycle time in VISSIM. Webster & Cobbe (1966) model used to design signals and modified to achieve optimum delay. Manual control results lesser delays than the existing signal time case. But updated signal times result even lesser delay than the manual control. When the junction is over-saturated, delays for manual control by traffic police result lesser delay than the existing signal times. Delays for minor road movement delays for signal control have significant reduction of delay than manual control. Daily variation of traffic also affects the junction delays significantly as the fixed cycle time signals are used. Introducing vehicle actuated signals will be an effective solution.
item: Thesis-Abstract
Evalaute vehicle operating cost by vehicle categories
(2024) Ellegama, EGHDB; De Silva, GLDI
The transportation demand has been increasing and the planners and engineers have been trying to find the best solutions to overcome this problem. The cost of travel plays a major role in one’s decision to select the transport mode in their day-to-day transportation decisions. Although travel time is considered the main attribute in their decision-making, the cost of using a vehicle is also considered as an important attribute. Therefore, the vehicle operating cost (VOC) is considered a vital piece of information that is frequently used in transport planning, mainly in demand model estimations and economic feasibility studies. VOC can be separated as a fixed cost and variable cost based on what the cost being accounted for. Fixed cost is the component paid periodically, yearly, irrespective of the vehicle is used or not. The licensee fees, insurance fees, and gas emission fees are examples of fixed variable costs. On the other hand, variable costs, are the cost components that add up with the distance of travel. The fuel cost, tire cost, maintenance cost, and labor cost are examples of variable costs that are commonly considered. Vehicle type and its conditions can influence operating cost variables, where the vehicle condition can be identified according to the model year and the registered year of the vehicle. Road condition, travel speed, and road geometry are among other factors that can contribute to vehicle operating costs. The VOC is unique to each country and understanding the vehicle operating cost and estimating it based on statistical methods for Sri Lanka was the objective of this research. The study looked at collecting data through data loggers of several vehicle categories over 1-year period. The data included fuel consumption cost, tire cost, maintenance cost, service cost, insurance & permit cost. The data was collected mainly for motorcycles, double cabs, and private cars, The study was able to establish the VOC for the main vehicle categories expressed as a cost per km traveled and the study also established the variation of the operating cost as a function of the total distance traveled over one calendar year. According to the data analysis data in 2019, Y= aX-b + c type interpolation gives the best-fitted line for the relationship between VOC per km (X) and travel distance in kilometer(Y). Keywords: Vehicle Operating Cost, Fixed Cost, Variable Cost
item: Conference-Abstract
Evaluation and improvement of toll collection system in Sri Lankan expressways - case study for Colombo-Katunayake Expressway
(Department of Civil Engineering, University of Moratuwa, 2018-08) Kumara, HBNS; De Silva, GLDI; Pasindu, HR
With the latest development, three expressways were opened to the public in Sri Lanka and the number of users of the expressway network is expected to rise. The pay toll system in the road is based on the traditional method, which is the collecting of the toll by road barriers installed at the entrance & exit points of expressways. Although in this system the toll is collected directly from the drivers, the existence of barriers causes increased travel time, increased fuel consumption and consequently increased pollution in the road environment. For a more continuous flow of traffic, an Electronic Toll Collection (ETC) system was introduced in Colombo – Katunayake Expressway (CKE) since June 2015 to help alleviate traffic congestions, reduce environmental pollution, reduce cash circulation, integrate the financial system, elevate passenger comfort, and specifically reduce the service time at Toll Plazas. This research focuses on the economic and technical analysis of the existing toll collection systems in the Colombo-Katunayake Expressway. The study is aim to evaluate the newly established ETC Toll collection System CKE. In detail, the objective is to assess the amount of delay of the individual lanes dedicated for MTC and ETC, their service time, lane capacities and the forming of the queue in each lane and compare with the different modes of toll systems used in other countries. The study also aims to find out the specific factors that affect the delays experienced at Toll plazas & decrease the system performance, and recommend ways to improve the service. Not only that, the study is focused on the evaluation of the economic loss caused by the delays in toll lanes and level of lane utilization by each mode of vehicles. The analysis of the current toll systems in CKE under the system, financial, traffic, environmental, infrastructure and socio-economic aspects would be conducted using SWOT method. Then, the different toll collection methods & technologies are to be studied under this research and characteristics and performances of each individual technology is to be compared. Analysis would be done to identify the appropriate ETC toll collection method for Sri Lankan Expressways. Consequently, short-term and long-term recommendations, for the Sri Lankan road tolling system, will be proposed, in terms of transportation.
item: Thesis-Full-text
Evaluation and improvement of toll collection system in Sri Lankan expressways : case study for Colombo-Katunayake expressway
(2018) Kumara, HBNS; De Silva, GLDI
With the latest development, three Expressways were opened for public in Sri Lanka and it is expected that the number of riders for expressway network will rise. The pay toll system in road is based on the traditional method which is collecting the toll by road barriers installed at the entrance & exit points of Expressways. Although in this system the toll is collected directly from the drivers, the existence of barriers causes increased travel time, increased fuel consumption and consequently increased pollution in the road environment. For a more continuous flow of traffic, an Electronic Toll Collection (ETC) system was introduced in Colombo – Katunayake Expressway (CKE) since June 2015 to help alleviate traffic congestions; reduce environmental pollution, reduced cash circulation, integration of the financial system, more passenger comfort, reduce the service time specifically at Toll Plazas. This research focuses on the economic and technical analysis of existing toll collection systems in Colombo-Katunayake Expressway. The study is aim to evaluate the newly established ETC Toll collection System CKE. In detail, the objective is to assess the amount of delay of the individual lanes of dedicated for MTC and ETC; their service time, lane capacities and the forming of queue in each lane and compare with the different modes of toll systems used in other countries. The study also aims to find out the specific factors that affect the delays experienced at Toll plazas & decrease the system performance and proposed suitable, recommend ways to improve the service. Not only that the study is focused on the evaluation of economic loss due to the delays in toll lanes and level of lane utilization by each mode of vehicles. The analysis of the current toll systems in CKE under the system, financial, traffic, environmental, infrastructure and socio-economic aspects would be conducted using SWOT analysis. Then, the different toll collection methods & technologies are studied under this research and compared characteristics, performances of each individual technology. Analysis is done for identify the appropriate ETC toll collection method. Further, fuzzy logic based MADM (Multiple Attribute Decision Making) approach is employed for selection of optimal ETC system for Sri Lankan Expressways. Consequently, short-term and long-term recommendations for Sri Lankan road tolling system are proposed in terms of transportation.
item: Conference-Abstract
The evaluation of factors influencing cycle trips in a heritage city. a case study on cycling tourist in Anuradhapura sacred city
(Department of Civil Engineering, University of Moratuwa., 2019-09) Wanniarachchi, SS; De Silva, GLDI; Pasindu, HR
As the world endures an energy dilemma, most developing communities advance toward energy efficient modes and non-motorised transport modes such as walking, roller skate, skateboard and cycling. Cycling is an environmentally friendly mode that enables the commuter to experience the surroundings. Other than commuting, cycling-tourism is about a long to medium distance cycling trip for pleasure, experience, and liberty rather than exercise or sports. Being one of the major tourist attraction zones in Asian region, Sri Lanka experiences over two million tourists’ arrivals every year to visit South and East Coast, Ancient Cities, Hill Country and Northern Region. Anuradhapura is one of the well-known ancient cities with many historical monuments connected with roadway links. This study identifies the design and influencing factors of local and foreign tourists to encourage cycling within the Anuradhapura ancient sacred city rather than using 3-wheeler taxi or other motorised travel methods. As phase 1 of the research, an initial survey was carried out inside the Anuradhapura sacred city with a sample of twenty-one respondents out of the target population of local and foreign tourists. Data has collected through a questionnaire survey and discussions. The factorial extraction has been run to determine the factors influencing cycling tourism, and descriptive statistics have used to present the socio-demographical features of the study sample. The secondary aim of the research is to review the variations in soft mobility choices by local and foreign tourists based on the design and the extracted manipulating factors. The analysis of data has generated factors with very strong loadings to represent the variables used in the survey. The descriptive analysis shows that the majority of the tourist visit Anuradhapura for pleasure, religious and business. Most of the tourist respondents had arrived from East Asia and Europe. The study explains that majority of them has used motorised transport to arrive at Anuradhapura and after arriving has used cycling within the sacred city. The analysis has highlighted that greater number of tourists prefer to use cycling for a short distance journey. The respondents have commented that safety and security issues have been a major tragedy in riding cycles inside the sacred city. It had mentioned that potholes in the road and the areas where the road has been damaged and unpaved had caused notable accidents to the cycling tourists. The risk of theft and the awful surroundings in some areas of the sacred city has discouraged cyclists from riding through the area. The further discussions with cycling renters and cyclists have highlighted that the cycling tourist, both local and foreign have been relying on verbal instructions of landmarks and road, as the Anuradhapura tourist city map provided by the Ministry of Tourism - North Central Province and the google maps has not been providing the accurate information on the routes and pathways inside the sacred city. The effort of the research is to help town planners prioritise services and improvements designated to the location to promote cycling tourism. Sri Lanka’s tourism is one of the revenue generations industries through cycling tourism in the early stages of development. This study has taken a general view concerning the influencing factors of Anuradhapura scared city cycling tourism to develop the cycling within the sacred city and to develop the soft mobility within the Anuradhapura district ensuring more eco-friendly urban surrounding.
item: Conference-Abstract
Evaluation of optimum service area for bulk depots for petroleum distribution
Fernando, PDL; De Silva, GLDI; Pasindu, HR
Ceylon Petroleum Storage Terminals (CPSTL) is responsible of distributing fuel throughout Sri Lanka. The fuel is transported from main terminals to bulk depots and subsequently to fuel stations using rail wagons and tank lorries. The costs from the two modes are considerably different and therefore, a need has arisen to optimize the fuel distribution process in order to minimize transportation and operational costs. The optimization has to happen in both the main terminal to bulk depot transportation and subsequent transportation to fuel station. Main terminal to bulk depot transportation consists of finding the optimum usage of rail and road modes and several researches had been done covering optimizing this distribution process. This research will introduce a model to optimize the distribution from bulk depots to fuel stations by optimizing the service area of each bulk depot.
item: Conference-Abstract
Formulation of a rapid transit route network for Colombo
(Department of Civil Engineering, University of Moratuwa., 2016-08) Devasurendra, KW; De Silva, GLDI; Sirisoma, RMNT; Bandara, JMSJ; Pasindu, HR
Colombo, as many major cities in the world with a growing population and an expanding economy, is facing the challenge of meeting the demands of increasing mobility needs within the city in terms of quantity and quality. Over the past few decades, land transport in Colombo has evolved in to traffic clogged roads especially during the peak hours making access and mobility between households, work places and other important locations a time consuming and a tiring task. Therefore, improving the mobility and accessibility in the inner core of the city, has become one of the major requirement of the country. A review of literature for the possible interventions suggested that an elevated mode of rapid transit is the best due to the unavailability and high costs of lands in this area. The other supporting reasons for such a system are the comfort, ease of access, less obstruction for the existing road traffic and hence low travel time between origins and destinations. Therefore an elevated system is likely to attract more private vehicle users, provide more options for public transport commuters and reduce road traffic congestion while improving the accessibility and mobility. Formulating the most effective and efficient route network to solve the mobility issue is therefore at utmost importance. The access locations of the rapid transit system which is the most important component of the network, were identified with due regards to the major trip generation points (Residential areas, apartment buildings and etc.) and major trip attraction points (office complexes, schools, recreational facilities, transport nodes, super markets and public places like hospitals and etc.). Possible major stations (nodes) were selected within the walking distance (500m) of majority of these trip attraction and generation points considering the land availability and security reasons as well. The routes were identified through minimum spanning tree process in order to minimize the cost of construction by minimizing the total length required to cover the identified locations and by taking the difficulty of construction (sharp bends and etc.) and required land acquisition in to account. Possible connections between the nodes along the existing roads that are possible to connect were identified with their distances. All these links were converted to equivalent cost figures which has taken the length, difficulty of construction and required land acquisitions in to account. A cost matrix was then formed between the nodes. In order for the cost to be a minimum, these nodes have to be connected with the links with minimum possible costs. Therefore, the minimum spanning tree method was utilized to connect the nodes. Using the cost matrix, a minimum spanning tree was developed to connect the identified nodes (possible RTS stations). From the developed minimum spanning tree network, the RTS network was derived while giving due attention to the construction and operational aspects. Special attention was given to the possibility of creating loops and connecting links with other available transport modes such as railway and bus transport.
item: Conference-Abstract
Identifying effective brightness limits for headlights of operating vehicles in Sri Lanka
(Department of Civil Engineering, University of Moratuwa., 2017-07) Senarathna, RMSK; De Silva, GLDI; Pasindu, HR
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 in 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 to 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 manufacturers 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 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 to the vehicle manufacturers but also to 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 the new regulatory system should be considered to control this vast variety and mitigate the risk and uncomforting 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 to above. 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. The results of field tests revealed that the majority of operating vehicles have less brightness levels comparing with the minimum brightness level specified in the Federal Motor Vehicle regulation. 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 on 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 regulatory system in Sri Lanka.
item: Conference-Abstract
Logit choice model for a passenger boat service in the Wellawatte Canal
(Department of Civil Engineering, University of Moratuwa., 2016-08) Sutharman, P; De Silva, GLDI; Pasindu, HR
Colombo is been transformed in to a modern city with the proposed Megapolis development in the Western Region. However, the quality and service of the public transport system is lacking which has prompted the use of private vehicles by the users to make their daily travel needs, which has resulted in heavy congestions during the peak times making the mobility to a standstill. Introduction of new transport modes have been the focus and one of the initiatives is to use the inland waterways as transport modes. A selected section has been the Wellawatte Canal that connects Wellawatte with Battaramulla making a essentially critical east west link within the city. The objective of the paper is to develop a choice model to empirically understand the perception towards the boat service by the passengers. It explores how much time and money people are willing to spend for this particular journey with respect to different mode choices available for them. A stated preference survey was conducted to collect data from the potential users of the system and ALOGIT software was used to develop a logit choice model. Each individual was provided with 4 public and 3 private transportation options to select the preferable choice of travel. The paper aims to discuss the individual‟s perception towards parking fees, fuel cost, access times, ride times and the fare for each mode which will provide a guideline to promote public transport among the transport users.
item: Conference-Abstract
Logit choice model for boat passenger transportation in Colombo, Sri Lanka
(Department of Civil Engineering, University of Moratuwa., 2019-09) Kaushalya, SMD; De Silva, GLDI; Pasindu, HR
Public transportation service in Colombo canal network is a viable alternative or addition to road and rail road on Colombo Metropolitan Region (CMR) corridors. Though environmentally friendly and frequently, the most economical mode of canal boat service, it remains largely under exploited in Sri Lanka. The prevailing public transportation modes such as bus, train and private transportation modes such as cars, motor bikes and taxis play vital roles in passenger movements within the country. But with the increasing population and the land scarcity in CMC region vast traffic and congestion problems exists in prevailing conditions. Thus, introducing another transportation mode is essential for future. Lack of data availability in the transport mode choice modelling has create problems implementing passenger boat transportation in CMR that leads to do more researches in the field. This study intends to present an idea of developing suitable passenger choice model on the basis of discrete choice modelling technique. ALOGIT software has been used for model setup and data analysis process. A stated preference pilot survey has been carried out in CMR region by proposing a public boat service route from Wellawatta to Battaramulla. The model was done for single level logit model. ALOGIT model was estimated to develop utility function to get an idea about people’s behavior patterns based on their socio-economic characteristics like age, gender, income level and based on travel characteristics like journey time, journey cost, waiting time, transit time. Further, separate travel characteristics, boat journey time and boat journey cost has been introduced to the model setup to identify public opinion of suitable fare terms for public boat transport service along the Colombo canal network. Results of this study provides an insight to incorporate boat transport service within the mainstream of CMR transportation planning.
item: Conference-Abstract
A methodology to develop a demand model for school trips in Western Province
(Department of Civil Engineering, University of Moratuwa., 2019-09) Damsara, KDP; De Silva, GLDI; Sirisoma, RMNT; Pasindu, HR
School trip is defined as a trip generated from a household or a hostel premises and ends at an educational institution (school) or vice versa. Origin-destination data is important to understand the travel patterns and also to estimate the future travel demand on transportation network over a particular catchment area. According to the administrative system of education, Sri Lanka consists of 25 districts which has 98 number of education zones having 312 education divisions. There are 10,194 total number of functioning government schools (National schools - 3.5%, Provincial schools – 96.5%) in Sri Lanka which have been categorized into 1AB – Schools having advanced level Science stream classes (1,029), 1C – Schools having advanced level Arts and/or Commerce stream but no Science stream (1,818), Type 2 - Schools having classes only up to grade 11 (3,288), Type 3 – Schools having classes up to grade 8 (4,059). Total school children population of the country is 4,165,964 and it has been divided among those 4 school categories as 1AB - 40%, 1C – 25%, Type 2 – 19%, Type 3 – 16%. Western province consists of 1,359 number of functioning government schools (965,113 students) in 3 districts which has 11 education zones and 38 education divisions. This study is focused on school trips, where the destination schools are located in western province. List of schools located in western province (as destination) is available in data management portal maintained by the Data Management Branch of Ministry of Education. Currently there is an ongoing project named as NEMIS-SIS (Student Information System of the National Education Management System) which collects data related to students who are currently enrolled in Sri Lankan Government schools. From that, origin city/town of the students which is required anonymously for this study can be collected. Based on those data Origin-Destination matrix can be prepared and a strong sample which covers all four types of schools discussed above can be selected. When selecting the sample, it is important to consider about the number of students and the number of teachers available in the school as well as whether the school is a boy school/girls school or mixed school. In Sri Lankan contest, travel patterns of school children depend on various variables such as school type, distance from home, access to transport, cost of travel etc. Therefore identification of origin-destination patterns and their relationship to those variables are used to develop a school trip demand model.