Browsing by Author "Mendis, BHA"

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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
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.