TRF - 2019

Permanent URI for this collectionhttp://192.248.9.226/handle/123/17956

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item: Conference-Abstract
Accident analysis on A9 road section from Elephant Pass to Pallai
(Department of Civil Engineering, University of Moratuwa, 2019-09) Sivagumar, V; Bandara, JMSJ; Pasindu, HR
Accidents considered as major hazard for any highway section. Highway safety can be improved with geometric features such as increasing lane width, improved horizontal and vertical curves, designated U-Turn and vehicle restriction, driver discipline, regulatory action and educational programs to public etc. The study intends to identify major accident causing factors in the particular sections, thus with better understanding of the factors improve safety of all stakeholders. The 20 km of Elephant Pass to Pallai section of A9 road considered as one of the two sections which connects north peninsula with other parts of the country. With the improvement of the sections from 2010 the vehicle entering rate of the section have increased and due to its good road condition vehicles are able to move at higher speeds. Motorcycles, buses, vans are the primary vehicles using this particular section. The accident data were collected from 2010 to 2015 and its locations were identified. Accident which caused fatal impact, hospitalization of victims and property damage more than 0.1 million were selected for this research. Using GIS system, the accidents and its locations were processed. During the study, blackspots were identified by developing weightage by the impacts and number of accidents. The reasons for accidents were analyzed and categorized under human errors, traffic conditions, improper geometric designs, road conditions and environmental factors. Accident causes patterns were identified by analyzing the causes in five years period. Critical reason was identified as geometry design of the section. In order to verify this reason, another 20 km road section was selected in A9 road, where the geometric design is different from the study section. Hypotheses testing was carried out to validate the accident results of the two different sections. From the study, the accident growth rate per km was identified. Remedial measures to reduce the accidents are studied in this research. One of the major limitations was only police recorded accidents were analyzed in this research. Other limitation was reasons for the accident are ambiguous in many cases.
item: Conference-Abstract
Analysis of the level of safety of public transport in a ‘sustainable development goals’ perspective in the national context
(Department of Civil Engineering, University of Moratuwa, 2019-09) Thilakshan, T; Bandara, JMSJ; Pasindu, HR
In 2015, Sri Lanka along with 192 member countries of the United Nations identified the timeliness of the concept of ‘Sustainable Development Goals’ (hereforth referred to as SDGs) and mutually expressed their desire to work individually and collectively to achieve the SDGs by 2030 post the Millennium Development Goals tenure from 2000 to 2015. It can be observed that the diverse nature of the context of the goals and their targets is a cross cutting concern dissecting many sectors and concerns listed by the 17 goals and 169 targets. Sustainable Transportation in the context of the United Nations has been classified into five dimensions: Accessibility, Affordability, Safety, Security and Environmental concerns. In this context, Public Transport plays a significant role in the sustainable transportation spectrum. Public Transport Safety is analyzed in this study in a global and national perspective in the context of the overall safety in transportation. The study narrows down to the concept of Public Transport safety which is identified as the one of the largest negative concerns in the current arena with a large number of commuters using the same mode at a given point of time involving high human intervention. Two targets listed in the SDGs give direct leverage to Road safety which also apply in the case of Public Transport: SDG target 3.6 - Halve the number of road traffic deaths and injuries by 2020 and SDG target 11.2 - Provide access to safe, affordable, accessible and sustainable transport systems for all by 2030. The Global Sustainable Transport Conference which was held on the 27th and 28th of November 2016 in Ashgabat, Turkmenistan highlighted the importance of sustainable transport in promoting economic and social development while protecting the environment and the main concern was the large number of annual deaths from road traffic accidents along with the environmental impacts of transportation. In both regards, Public Transport plays an important role and the safety assurance of Public Transport is one of the main dominating factors in attracting people to Public Transport modes, which mainly constitutes buses and trains in the national context. Thus, the study identifies the importance of Public Transport safety to achieve sustainable transportation and SDGs while analyzing the current status of Public Transport using available data and statistics in a national perspective. Apart from studying the pattern of Public Transport in terms of deaths, injuries and related parameters, more concern in the study focusses on the post 2015 SDG timeframe to evaluate the impact of the SDG framework in the context of road safety and the practicality of achieving the SDGs: target 3.6 by 2020 and target 11.2 by 2030 in the perspective of Public Transport. 90 percent of road traffic deaths occur in low and middle-income countries even though the countries count to only 54 percent of the world’s vehicles percentage. Sri Lanka is no different in terms of the crucial impact of road safety and analyzed data from the National road safety council of the Ministry of Transport and the Sri Lanka Police show no decrement in terms of road safety accidents and resulting deaths, injuries and damages. The analysis looks into the impact of Public Transport to the overall safety scenario and the steps that needs to be taken in dealing with Public Transport based safety issues with utmost importance due to the large number of lives involved in the scenario and the attraction factor of people towards using Public Transport as an alternative for their private vehicles. The number of private passenger transport buses and Sri Lanka Transport Board (SLTB) involved in the accidents and their rate of involvement in an annual and monthly timeframe is analyzed along with the accident type. Thus, an analysis on public transport buses is carried out in an individual and overall (Private and SLTB buses) manner for better understanding. An analysis framework of the Railway sector and accidents in a periodic timeframe along with the category of railway accidents involving the railways is included in the study. Thus, the study analyzes the overall Public Transport in the national context with respect to safety and the reasons involved in the accidents along with evaluating the current position of the transport sector in terms of sustainable transportation in terms of public transport and achieving the SDGs in the national context.
item: Conference-Abstract
Analysis on fundamental factors affecting fuel economy of light duty vehicles
(Department of Civil Engineering, University of Moratuwa., 2019-09) Gajanayake, SP; Sugathapala, AGT; Bandara, JMSJ; Pasindu, HR
Fuel economy is one of the two major performance indicators of a vehicle whereas the other key indicator is the emission of mass pollutants. Recent policy related initiatives that have taken in place in vehicle manufacturing countries/regions viz. EU, USA, and Japan depict that a strict attention has been paid to control the fuel economy of the newly manufactured vehicles, especially light duty vehicles (LDVs). In order that, obtaining a better level of understanding on the fundamental factors affecting the fuel economy of vehicles is significant. Goal 7 of the Sustainable Development Goals (SDGs) aims to ensure sustainability and accessibility of energy and as a part of it, target 7.3 aims to double the global rate of energy efficiency, which includes the improvements in vehicle fuel economy. Also Goal 13 of SDGs aims to take urgent action to combat climate change and its impacts. Since transport sector is accountable for almost a quarter of CO2 emissions, the improved fuel economy can help reduce it. Factors affecting the fuel economy of LDVs can initially be categorized into 2 main types i.e. vehicular factors and non-vehicular factors. Non-vehicular factors can secondarily be categorized into 5 main types i.e. weather-related factors, traffic related factors, Street environment related factors, Travel behavior related factors and Driver behavior related factors. Vehicular factors can secondarily be categorized into 2 types i.e. Static vehicular factors and Dynamic vehicular factors. Static vehicular factors can be defined as the vehicular characteristics that do not vary in the temporal domain whereas the Dynamic vehicular factors can be defined as vice-versa. During the analysis, the Static vehicular factors affecting the fuel economy can again be listed into 4 sub-categories as mentioned below. Static Vehicular Factors • Power Generation related • Power Transmission related • Traction related • Other Static Factors The sub-factors that can be listed under power generation factors are engine configuration, type of energy/fuel used, number of cylinders, cylinder capacity, type of ignition, firing order, engine valve configuration, camshaft configuration, method of fuel injection, compression ratio, power-boosting mechanisms and engine placement. The sub-factors under the power transmission can be listed as type of transmission, speed ratio configuration, gear-changing mechanisms used and etc. The traction related sub-factors can be listed as type of driving-wheels (i.e. front-wheel drive/rear-wheel driver or all-wheel drive), wheel factors (i.e. size and weight of the wheel, without the tyre), tyre-related factors and brakes-related factors. The other static vehicular factors affecting the fuel economy can be mentioned as vehicular body dynamics and vehicular weight(no-load). The Dynamic vehicular factors can be listed as kinetics related factors (viz. torque, friction, drag, etc.), kinematics related factors (viz. velocity, acceleration etc.) and vehicular maintenance related factors (viz. vehicle-aging, vehicle-mileage, service routines, etc.). Identifying and classifying the fundamental factors affecting fuel economy is primarily significant whereas developing functional relationships between fuel economy and fundamental factors will be performed secondarily. Governing equation(s) for fuel economy will be developed subsequently. Hence, the respective analysis is performed in order to explicitly identify the fundamental factors which affect the fuel economy of LDVs.
item: Conference-Abstract
Barriers in modal integration: the case of rail and bus transportation in Sri Lanka
(Department of Civil Engineering, University of Moratuwa., 2019-09) Bandara, YM; Rathnayake, T; Pasindu, HR
For the existence of competitive markets, transportation is an essential economic activity needed to fulfill the activities of daily needs by providing a mode for the mobility of people and freight. A selection of specific planning method of transportation, convincing the passenger to use public transportation over private transport modes is a vital element in the current transport policies. Efficient operation of transport services depends on how effectively transport planning is undertaken considering technical, economic, market, social and environmental requirements under which services are provided. Nowadays every country in the world is trying to establish its own national transport system, not in isolation but as a part of the international system of transportation. When a transport mode is incorporated into a model, it can be used to build a better transportation system by using split development, model share and model integration. However, the passenger flow would not take place as predicted by transport models due to the influence of personal transport modes. As a result, developed infrastructure and transport services are often underutilized or one attractive mode of transport services are highly demanded to lead to overcrowding. This leads to the development of modal share issue with public transport share tends to decline while private motorized transport share is on the rise. As a remedy, model integration is considered as one seamless entity which has made by the involving of the travel modes for the benefit of the fare paying customer. There are many integrated transportation systems can be seen in well-developed cities all around the world established to reduce car dependency (Buehler, Pucher, Gerike & Götschi, 2017). Transport modal integration (Intermodality) provide the advantages by keeping space through the traffic congestion and controlling and resultant time saving and vehicle operational costs savings to users, minimizing carbon footprint and other negative externalities and eventually reducing the country dependence on fuel. However, intermodality is not always successful due to certain barriers. This paper aims at identifying the barriers that affect to efficient model integration process between bus and railway service around selected bus and rail corridor. The methodology followed in this research is a questionnaire-based data analysis using Principle Component Analysis (PCA). The relevant data were collected through a field study conducted in a selected public transport corridor that is served by rail and bus transport. The data collection was carried out using an online survey form but carried out as face to face. At all location 100 randomly selected passengers were surveyed. Data from each location were collected to cover all the time frames as possible and covering different users of the transportation service. Main factors acting as barriers to modal integration were derived as operational factors, comfortability, infrastructure design, competition, information flow and ethical behavior from the PCA analysis. Fourteen barriers identified, which includes security and safety concern of train, lack of information of bus and railway operating times, the capacity of current bus and train service and operating conditions of bus and railway stations, have been perceived as the main issues to be solved that make passengers participate in model integration between bus and railway services. Further, poor sanitary facilities, having uncomfortable fare collection methods and health and fitness issues of passengers have also been barriers. Further, considering the travel complexity of passengers in the sample, 28 travel patterns have been identified which includes traveling modes of the bus, foot, train, three-wheelers, taxi cabs and personal vehicles such as cars, bikes, and vans. Most of those 28 patterns have similar areas of destinations even they have different origins indicating hub and spoke transport behavioral pattern. Variable origins, less planned travel facilities, not having proper integration method, have been main reasons for the travel complexity.
item: Conference-Abstract
Characteristics of school trips in Colombo
(Department of Civil Engineering, University of Moratuwa, 2019-09) Mishael, MJ; Amarasingha, N; Pasindu, HR
This study explores the characteristics of travel mode choice of school trips made by students whose age between 11 to 18 years. The objectives of this study were to investigate the factors affecting travel mode choice of school trips and to recommend mitigation strategies to reduce traffic congestion due to school trips in Colombo. Questionnaire surveys were conducted among school students in Colombo to gather information related to the mode of transport to and from schools. The factors that explain the reasons for the choice in the particular mode of transport were investigated. A model is developed to understand the relationship between each of the determinants and the choice of mode transport to analyze how this study can be utilized to benefit the overall modes of transport available for school children. The pilot study was conducted among randomly selected 65 students from the Colombo district. The study went on to identify the mode of transport commonly used by students. It was identified that 53% of students used private mode of transport whereas just 34% of students used public transport when traveling to school. Moreover another 11% of the respondents went to school by walking. As per this study, it was identified that nearly 42% of the students were accompanied by parents or guardians when traveling to their respective schools. However, a similar 45% of the students who were taken into a pilot study, traveled to school alone. When considering the average distance to school from home, 79% of students traveled less than 10 km to school. Hence, this study clearly identified that the use of private transport methods has been a major factor contributing to the traffic congestions in the area, hence, improved public service transport, improved cycle paths and set-up of appropriate pedestrian paths are identified as major factors that can resolve this pertaining issue.
item: Conference-Abstract
Criteria to identify candidate roads for public private partnership development
(Department of Civil Engineering, University of Moratuwa., 2019-09) Tharmakulasingham, K; Pasindu, HR; Pasindu, HR
In many cases, Public Private Partnership (PPP) projects are looked as skeptical phenomenon due to the risk factors involvement. However, in order to reduce the burden of government, it is essential to undertake PPP projects. Lack of project prioritization due to absence of supporting framework for selecting the projects in Sri Lanka was identified as one of the key findings by World Bank for accelerating PPP projects. Therefore, a study was conducted to identify the critical success and failure factors of PPP road projects in other countries, thus assist the public and private entities to identify the potential road projects in Sri Lanka. The aim of this research is to prioritize project from pipelines for PPP developments. Success of the projects are measured based on the risk allocation efficiency and productive efficiency. As a first step, criteria which are used by other nations for selection of PPP projects were collected. Further, Critical Successful Factors (CSF) of PPP projects were reviewed during the project preparation, procurement, development, construction, operation and maintenance stages. Top most factors were selected from various researches. Meanwhile, in this research we have considered not only the success case studies but also the failure road projects to critically analyze the factors influenced in the failure of those projects. In many cases, one of the prime reasons for failure was the absence of CSF. The importance of these factors in the selection criteria was analyzed. Having prepared the CSF, readiness of accepting the PPP model, constraints for the development and challenges for the implementation of PPP model in Sri Lanka can be evaluated. As an improvement of the research, questionnaire survey can be carried out and the stakeholder opinions can be taken. Major limitation in this study is that, there are no any PPP road projects in Sri Lanka, to compare our exploration and the real-world project scenario. In addition, another limitation was the lack of availability of detailed documentation in the projects.
item: Conference-Abstract
Decade of action for road safety: trends in road accidents, Sri Lanka
(Department of Civil Engineering, University of Moratuwa., 2019-09) Ranawaka, RKTK; Pasindu, HR; Pasindu, HR
At present, nearly eight people die due to road accidents each day in Sri Lanka. This amounts to over 3000 fatalities per annum. This is an increase of 35.2% when compared to the fatalities in the year 2008. During the same period, the registered number of vehicles has increased by 113%. With the rapid motorization and decrease of public transport usage which has taken place over the last decade, new trends in road accidents have emerged in Sri Lanka. The study used accident data from 2008-2017, to identify how the accident types and patterns have changed over the period. In the year 2008, most of the accidents have happened in roads classified as urban, with a percentage of 53%. By 2017, 53% of the accidents have happened on roads classified as rural. Within the period from 2008 to 2012, most of the accidents have happened between 16:00-18:00. The trend has shifted to the time period of 18:00-20:00 from 2013 onwards. During the study period, the motorcycle was the highly exposed vehicle type to accidents. Motorcycles account for 23% of the total vehicles, engaged in accidents in the year 2008. It has increased up to 27% of the total vehicles engaged in accidents in the year 2017. Most numbers of motorcycles involved accidents are pedestrian-motorcycle accidents. The percentage of motorcycle-car accidents has increased from 10% to 14% from the year 2008 to 2017. Most numbers of three-wheelers involved accidents are three wheeler-motorcycle accidents. The percentage of three wheeler-car accidents has increased from 15% to 21%, when considering three-wheeler involved accidents. The age group with the highest number of casualties is 21-30 years when considering both motorcycle and three-wheelers involved accidents. Pedestrian accidents have increased by 10% when compared to the year 2008. Among pedestrian involved accidents, pedestrian-motorcycle accidents have the highest rate in each year. The highest exposed age group for pedestrian related accidents is 41-50 years each year. It is generally around 15% of the total pedestrian accidents each year. Among lorry involved accidents, lorry-motorcycle accidents have the highest rate in each year. Lorry-motorcycle accidents have increased by 6% when compared to the year 2008. In the year 2008, most of the lorry related accidents have happened by lorry drivers within the age group of 21-30 years, which is 30% of all lorry involved accidents. By the year 2017, the trend has shifted to the age group of 31-40 years, which is 36% of all lorry involved accidents. The study could capture two weaknesses in the accident reporting system in Sri Lanka. 99% of the accidents have been recorded without identifying probable roadway and vehicle pre - crash factors. Results of this study will be useful input for policymakers to develop effective long term and short-term strategies to reduce road accidents.
item: Conference-Abstract
Development of bus service reliability measures at the stop level
(Department of Civil Engineering, University of Moratuwa, 2019-09) Sharic, AHS; Bandara, JMSJ; Pasindu, HR
Bus service reliability, one of the key performance measures, has become a major concern of both transit operators and users because it significantly affects user experience and service quality perceptions. Schedule adherence has been the most important existing reliability measure for infrequent services that operate with headways of more than 10 minutes. For routes characterized by high frequency service namely less than 10 minutes of headways, headway variability has been the most important existing reliability measure. But these measures do not differentiate between the cost of being early versus late. Different unreliability characteristics that cannot be captured by the existing measures calls for a supplementary measure. This research adopts two indices from (Saberi, et al., 2013) that overcome those issues such as Earliness Index (EI) and Width Index (WI). The Earliness Index is defined as the percentile rank of delay/headway deviation of zero. The percentile rank of a particular delay/headway deviation is the percentage of delay/headway deviations in its frequency distribution that are lower or equal to it. EI ranges between 0 and 1. For frequent services, an EI of 0 represents the “all behind schedule” condition and an EI of 1 represents the “all ahead of schedule” condition. For not frequent services, an EI of 0 represents the “all late” condition and an EI of 1 represents the “all early” condition. For infrequent services, the theoretical ideal distribution lays on the y-axis of the cumulative distribution function. Buses that are early can be treated as being one headway late, because passengers who are arriving near the scheduled departure time would have to wait for the next bus. Therefore, the “all late” condition is expected to be the achievable ideal distribution for non-frequent services to avoid early departures. Note that the above statement is true only when the theoretical ideal distribution (all “on-time” condition) is not achievable. The closer the EI is to 0, the more reliable is the service. For frequent services, one cannot argue similarly, since maintaining a fixed headway with a small deviation is more important than being ahead of or behind the schedule. Thus, another measure is required to capture the variation of headways. To capture the width of the distribution of headway deviations in frequent services, the Width Index (WI) is defined as the 95th percentile of headway deviations minus the 5th percentile of headway deviations divided by the average scheduled headway. .Data needed for theses are as follows. Using the existing time keeper records at the bus stops, a number of measures can be simply calculated. The scheduled headway at a particular stop can be computed as the scheduled stop time for trip i at a stop minus the scheduled stop time for trip i-1 at the same stop: Note that the proposed reliability indices are not suggested as replacements for the existing measures; rather, they are complementary.
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 methodology to estimate trip attraction and parking demand for urban office developments: case study- Colombo
(Department of Civil Engineering, University of Moratuwa., 2019-09) Priyadarshani, M; Pasindu, HR; Pasindu, HR
Urban commercial developments are an integral part of the urban land use and this affects the trip generation and attraction pattern in the city. More importantly these developments increase the demand for parking, which by law should be provided within the development. Lack of adequate parking facilities will impact the road network as it will lead to on-street parking and additional vehicular circulation to and from public car parking areas. Furthermore, provision of parking within the premises results in an increase in the cost to the developer which can escalate the prices of the property. Moreover, due to lack of local norms to indicate accurate traffic generation factors for different types of developments such as office complexes, business establishments etc., it is hard to forecast accurate future traffic figures that will generate due to the proposed new developments. Therefore, regulations need to ensure adequate number of parking are stipulated based on the type of facility. Parking regulations for office building type developments used for the city of Colombo is based on gross floor area of the building, which may not necessarily represent the parking needs of the building depending on the type of operation which takes place. Therefore, the existing parking regulations for these types of development need to be revised in order to assess the optimal parking requirement for different types of office buildings. The study develops a methodology to estimate trip attraction patterns and parking demand for urban office developments. For that research aims to evaluate the trip attraction patterns for different types of office developments and it investigates the effectiveness of current parking regulations and calculation methods in Sri Lanka. Similarly, it identifies new criteria to evaluate parking provisions for the new office developments. Finally based on study results parking demand and trip attraction rate will be assessed.
item: Conference-Abstract
Development of pavement condition prediction model for national highways
(Department of Civil Engineering, University of Moratuwa., 2019-09) Sandamal, RMK; Pasindu, HR; Pasindu, HR
National Highways are basic infrastructure which provide the connectively for the urban development in a country. An accurate pavement performance prediction model is essential for pavement asset management systems to optimize the life cycle cost of preventive and corrective maintenance strategies. In this study, pavement roughness and relevant distresses progression of national highways in the long-term pavement performance data was analyzed to develop such a pavement condition prediction model. International Roughness Index (IRI) is a global parameter to measure the ride comfort of road users and unevenness of pavement, therefore use as the basis for the pavement prediction model in this research. High intensity of repetitive axle loading, and aging effect caused for the failure of pavement and distresses related to traffic load and aging are developed, hence pavement roughness is increased while distresses are propagated. Structural failure, functional failure due to the non- smooth riding surface are the reasons for increasing of vehicle operating cost (VOC) and waste of resources. The relationship between roughness and relevant distresses progression with pavement age was developed and validated with comparing such models developed by previous studies. The pavement distresses progression with the pavement age is analyzed by using regression analysis. Three curves are plotted to express the pavement deterioration, in that roughness deterioration curve is developed by considering the initial construction quality. Those deterioration models can be used to calibrate HDM-4 software to adopt for the local condition as a decision-making tool for the maintenance and rehabilitation work. Increasing of roughness is a function of progression of distresses which is use for the model calibration process in HDM-4 software as shown in equation 1. ΔRI= Kgp + ΔRIs + ΔRIc + ΔRIr + ΔRIt + ΔRIe …….…………………(1) Where: Kgp - calibration factor of general surface roughness development, ΔRI - gradual increase of pavement surface roughness, ΔRIs - structural pavement deterioration, ΔRIc – deterioration due to cracking, ΔRIr – deterioration due to rutting, ΔRIt – deterioration due to potholes, ΔRIe – deterioration due to climate effects From the results of the study, the components of roughness deterioration due to the pothole (ΔRIt) and cracking (ΔRIc) are established. Combination of deterioration due to the structural condition, climate effect and rutting are representing as a constant. The findings from the research can be used to HDM-4 model calibration of roughness increasing of national road network in Sri Lanka instead of using default values which are currently use for the pavement performance modelling.
item: Conference-Abstract
Development of pavement performance and prediction models for flexible road pavements in Sri Lanka
(Department of Civil Engineering, University of Moratuwa., 2019-09) Karunarathna, EPN; Pasindu, HR; Pasindu, HR
International Roughness Index (IRI) is a pavement performance indicator which reflects not only the pavement condition but also the ride quality and comfort level of road users”. “Many highway agencies around the world consider the initial IRI value (IRI just after construction) as a quality assurance criterion while the prevailing IRI of a pavement as an indicator of required pavement maintenance actions or reconstruction needs. The aim of this paper is to develop an accurate IRI prediction model for Road pavements in Sri Lanka using linear regression analysis”. This model was developed based on data obtained from Road Development Authority (RDA) of Sri Lanka collected mainly using the Road Survey Vehicle. Models were developed for National Highways (A and B Class Roads) only. Further, variation of IRI for different climatic regions and for different vehicle compositions will be analyzed. The key parameters that the IRI value directly related on a particular pavement was decided based on the literature and the availability of data. The proposed regression model from this paper predict IRI as a function of pavement age, Average Annual Daily Traffic (AADT), initial IRI (IRI just after pavement construction) and transverse cracks or alligator cracks combined length per unit area of the pavement. A set of available data was used to calibrate the regression model and using other set of data, relationship between the measured and predicted IRI values for the proposed model was observed using the coefficient of determination (R2 value) as a statistical measure to determine how close the data are to the fitted regression line, as the validation process. The proposed model yielded an R2 value of 0.58. To identify critical parameters in above relationship statistical coefficient p-value was used. Then the variation of IRI was analyzed for different traffic categories. For AADT is greater than 50000 veh/day model yielded an R2 value of 0.36. For ADT in between 50000 to 10000 veh/day model yielded an R2 value of 0.21 and for category AADT less than 10000 veh/day model yielded an R2 value of 0.61. It was observed that due to some erroneous data the accuracy of the models became lower. So it was decided to remove pavement sections with age more than 25 years and some unacceptable values of IRI measurements using Engineering judgement and reanalyze. To identify the variation of IRI for different climatic conditions Western, Central and Northern provinces were selected. Western province has an annual average temperature of 27.4°C and an annual average Rainfall of 2420mm while Central province has 24.5°C and 1840mm and Northern province has 28°C and 1230mm. Models yielded R2 values of 0.18, 0.45 and 0.72 for Western, Central and Northern provinces respectively. Due to low R2 values it was decided to remove some unacceptable values of IRI measurements using and reanalyze.
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-Abstract
Effect of heavy vehicles on performance of ‘Colombo-Katunayake’ Expressway
(Department of Civil Engineering, University of Moratuwa., 2019) Subasingha, SAAKK; Mampearachchi, WK; Pasindu, HR
Colombo-Katunayake Expressway (CKE) is linking the Sri Lankan capital Colombo with the Bandaranayake International Airport and it provides great service to expanded industrial areas in the region. It makes great importance that maintain quality of the expressway as to cater better service for the public. One of the most important factors in the recent years is the pavement damage due to the overloaded heavy vehicles and the overloading effects caused by the increased heavy vehicles traffic volume. But heavy vehicles play an important role in the economy, and are expected to remain a common sight on our expressways in the foreseeable future. Accordingly, balance criteria should be used among these two factors as to minimize economical losses. Department of Motor Traffic Sri Lanka has implemented certain standards based on vehicle axle configuration. But the heavy vehicles drivers seldom follow these standards and regulations. This practice of overloading the vehicles will have a direct impact on the pavements getting more damaged. The research overview is analyzing the damage caused by overloaded vehicles and compare with the transport cost to optimize these two factors. Heavy vehicle traffic data is collected throughout the operating period and the data illustrates that the heavy vehicle traffic is being increased every year so that average monthly traffic in 2013 is 12,300 and now it has increased to 26,500 by 115% over 5 years. Two intermediate CCTV locations were selected and videos were used to identify heavy vehicle drivers’ lane behavior. It is understood that 94% of heavy vehicles drivers use outer lane as they enforced to do. In this study, two toll gate exits were determined where there are installed weight bridges as to measure gross weight and axle loads of randomly selected heavy vehicles and to identify distribution of heavy vehicles in CKE. Several other required data can be obtained through Planning Division, Road Development Authority. HDM4 software will be used to develop a model using available data as to find out effect of heavy vehicles in CKE so that service life reduction, kind of maintenance required and incurred cost will be evaluated. Finally, the study will optimize the road damage due to heavy vehicles and transport cost, and overloading penalties will be implemented on extra weight that the heavy vehicle is carrying.
item: Conference-Abstract
Effect of styrene – butadiene – styrene (Sbs) on mixing process and laying of asphalt concrete
(Department of Civil Engineering, University of Moratuwa., 2019-09) Varshihan, V; Mampearachchi, WK; Pasindu, HR
Construction of flexible pavements involve the production and utilization of asphalt concrete (AC) for the wearing course and the binder course. The sustainable production of AC mixtures has become a major concern internationally. Recycling of waste polymer materials can be identified as an effective method which improves the aspects of sustainability and economy of highway construction projects. This research was conducted to investigate the modification of asphalt properties using Styrene-Butadiene-Styrene (SBS) as a modifier and to check the performance of the modified asphalt mixtures in the aspects of the quality and the cost at plant scale production. At the initial phase, the selected bitumen binder was mixed with the SBS modifier to produce an AC mixture in which SBS acts as a binder modifier for bitumen, and as a filler modifier for aggregates. Mix design details for AC were obtained from the Marshall mix design. The first set of production was done for 6% of SBS to the total bitumen weight. SBS was added quickly to the pre-blending bitumen tank while stirring at 180 oC -190 oC temperature during the wet process. Then the mixture was allowed to flow through the high shear mixing and dissolving tank to produce a uniform mixture. Subsequently, the modified bitumen was mixed with the aggregates at a mixing temperature of 170 oC – 180 oC. Then the mixture was placed before it reaches the recommended laying temperature of 140 oC. The optimum compacting temperature was obtained by changing the temperature of the mixture. The asphalt mixture was heated at the respective temperature and it was kept for 10 minutes at boiling water temperature to find the mixing temperature for a better coating of the modified bitumen. At the final phase, the physical properties of asphalt mixtures were investigated using Marshall test parameters including the stability value, the flow value, the percentage of air voids, and the percentage of voids in mineral aggregates (VMA). Wheel tracking test was also conducted. Cost analysis of the above production process was investigated by varying the parameters of the plant operation such as the mixing time, the control temperature, and the set of plant modifications. Considering the outcomes of this research, it is recommended to improve the efficiency of the plant operation processes for the modification of AC. This will also enhance the sustainability by minimizing the hazards to the environment due to the waste polymer materials causing environmental pollution.
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 rheological properties and performance of asphalt binder modified with nano clay
(Department of Civil Engineering, University of Moratuwa., 2019-09) Shantha, YGPB; Mampearachchi, WK; Adikary, SU; Pasindu, HR
The rheological behavior of bitumen is very complex and it can be varied from purely viscous to elastic depending on the loading time and the temperature. Bitumen plays a major role in many aspects of road performance. Various investigations have been carried out related to the modified bitumen to improve the performance of bituminous mixtures. Most of the Roads are failed due to the rutting and cracking of the bituminous layer which is due to the mostly poor performance of bituminous binders. So, the modification of the bitumen has been major approach in today and modified bitumen is effectively used in many countries during last three decades to construct the pavements. This research presents a laboratory scale evaluation of the conventional and the fundamental rheological characteristics of modified binders with micro clay and Nano clay contain 2%, 4%,6% & 8% by its weights. Engineering fields are widely used montmorillonite (MMT) nano clay for wide range of applications. In Sri Lanka also, there had been few researches about the usability and characterization of MMT clay which is available at Mannar area near to the Giant tank. The clay powder prepared from the original samples taken from the above area was added to the original bitumen of 60/70 penetration grade binder to prepare the modified binder. The prepared clay powder was subjected to the X- ray diffraction to identify the MMT clay. Modified bitumen samples were prepared by adding nano clay mixed at 1600C with the mixing time of 25minutes. The properties of the modified binders with nano clay were evaluated in terms of their properties using penetration, softening temperature, ductility and dynamic viscosity tests. Finally, modified bitumen each sample were evaluated for the rutting and fatigue resistant for fresh and aged samples with the Dynamic Shear Rheometer (DSR) test. It was observed by the results obtained from the tests that the softening point and viscosity increased up to 4% clay, penetration and ductility has decreased with increasing of clay percentage. Rutting resistance has not improved with compared to conventional bitumen and it was showed that modified bitumen and original sample were showed PG 70 grade with 2%, 4%, 6% and original bitumen sample. Finally, few samples of modified binder with nano clay was checked with Furrier Transform Infrared Spectrometer (FTIR) to identify any chemical changes with compared to conventional bitumen. As a conclusion from these findings that is the montmorillonite clay modification helped to improve some characteristics of the bitumen binders. But at this level they are not at the stage to verify application at large scale.
item: Conference-Abstract
Evaluation of traffic forecasting accuracy in road projects in Sri Lanka
(Department of Civil Engineering, University of Moratuwa, 2019-09) Rajakaruna, D; Pasindu, HR; Pasindu, HR
Traffic demand forecasting is integral part in the highway planning and feasibility assessment. Forecasted traffic demand is used to determine the highway capacity, to estimate the design ESAL for pavement design and to evaluate road user benefits such as travel time, vehicle operating cost, emission and accident that are used in the economic feasibility assessments. This research investigates the accuracy of demand forecasts using a sample of projects in Sri Lanka and identifies the factors influencing the demand forecast accuracy. The selected roads include, expressways, national roads in urban and rural areas. The forecast traffic demand values are derived from the demand analysis carried out in feasibility studies of highway projects. The corresponding observed traffic data for this study is drawn retrieved from traffic databases available at University of Moratuwa and the Road Development Authority. The forecasted traffic volumes at the corresponding location is adjusted based on the growth factors given in the demand model used to calculate the traffic volume for the year in which the observed data is available. The study evaluates the variation of accuracy of demand variations with respect to the following factors, a) demand modelling tool used, b) differences in analysis scenario with respect to other transport infrastructure is the used in the model and condition at the time observed traffic volume was taken, c) variation in error with the forecasting period, and d) variation in error with type of highway. The results of this analysis would useful for highway planning and demand analysis studies to identify the demand variation risk and to incorporate it in improving the demand analysis processes.
item: Conference-Abstract
Feasibility study of using industrial waste as an internal curing aggregate for rigid pavements
(Department of Civil Engineering, University of Moratuwa., 2019-09) Pradeep, KI; Tharshigan, T; Mampearachchi, WK; Pasindu, HR
The hydration process of cement in concrete affects the temperature conditions and moisture content which indirectly cause for strength, shrinkage and cracks. Curing starts immediately after setting of concrete. American Concrete Institute describes curing as “action taken to maintain moisture and temperature conditions in a freshly placed cementitious mixture to allow hydraulic-cement hydration and, if applicable, pozzolanic reactions to occur so that the potential properties of the mixture may develop”. In external curing of rigid pavements, water inside the concrete consumed for hydration of cement, some part of water escapes to the atmosphere through concrete surface and some part absorbs to the ground. Thus. Internal drying occurs which reduces the relative humidity while increasing the internal stresses which results in shrinkage and thermal cracks. External supplied water will only affect for top part of the concrete layer. Internal curing method has been introduced as a solution to the problems encountered in external curing. According to American Concrete Institute, they defined internal curing as “a process by which the hydration of cement continues because of the availability of internal water that is not part of the mixing water”. It’s a method which supply water internally through water reservoirs which need for hydration process. This research is to develop a fine aggregate for rigid pavements which performs the internal curing properties using industrial waste. Water treatment sludge (WTS) and Textile Effluent sludge (TES) used as industrial waste to prepare fine aggregates. After several steps in treatment process to remove inorganic, organic contaminants and suspended solid particles in surface water, produce large quantities of sludge by removing impurities from raw water. Sludge removed from above process called ‘water treatment sludge’. Textile industry consume large amount water to convert raw materials and fabric to finished clothing materials. Specially for dyeing. So large quantity of sludge produces in the waste water treatment plants due to this case. The disposal of sludge from water treatment plants and textile dyeing industry is a huge issue for related authorities. Introduce a value-added product for waste sludge will be another solution for the waste. The water treatment sludge and textile effluent sludge was dried under sunlight and crushed in to powder form which passing through 0.6mm sieve. Thermogravimetric analysis and Differential scanning calorimetry are conducted to identify the thermal behaviour of sludges. Different mixtures were prepared by changing two sludge contents (100% WTS, 90% WTS+10%TES, 80%WPS+20%TES). Atterberg limits was initially identified to select the optimum water content need to mix the samples. For laboratory tests, cylindrical samples (Height; 80mm, Diameter; 17mm) were prepared for heating process. Slow heating method used to sinter the samples for different temperature levels (8000C, 9000C, 10000C, 11000C, 12000C). Then samples were crushed to small particles which passes through 4.75mm sieve and retained on 0.6mm sieve. Water absorption test, Relative density test, bulk density test was conducted to observe the physical properties of developed fine aggregates. Scanning Electron Micrographs (SEM) analysis was followed to observe the microstructure of the fine aggregates. Compressive strength test was followed to identify which temperature shows the higher strength of fine aggregates. According to ASTM C1761M, internal curing aggregate shall have a 72-h absorption not less than 5%. Also, the fine aggregate shall release at least 85% of its absorbed water at 94% relative humidity. When Kelvin equation combined with Young’s equation, a relationship between relative humidity and size of the pores being is established. According to the relationship, the pore size should be more than 200nm to release water from aggregate. The fine aggregates which developed using sludge waste shows higher water absorption which need for internal curing property. According to the SEM analysis, it shows that the pore size increases with the temperature and textile effluent sludge content. According to thermogravimetric analysis, compressive strength test and microstructure, it concludes that 1150oC is the optimum temperature to heat the sludge waste. The optimum textile effluent sludge and water treatment sludge were selected as 20% and 80% respectively, while 45% of water content should be added when preparing the mixture. As a conclusion to the above findings, the fine aggregates which developed using sludge waste feasible to use as an internal curing aggregate in rigid pavements.
item: Conference-Abstract
Formulation of a national framework for the digital transformation of Sri Lanka’s public bus transport system
(Department of Civil Engineering, University of Moratuwa., 2019-09) Dunuwila, VR; Jayakody, JADCA; Lokuliyana, S; Pasindu, HR
Public transport is considered to be a country’s primary transportation network that plays an increasingly important role in human navigation. Thus, many countries have digitally transformed their public transport services to ensure the delivery of a quality transportation experience to passengers whereas the use of digital practices in Sri Lanka’s bus transportation industry is minimal. As a matter of fact, majority of the vehicles entering Colombo are private vehicles that carry an immaterial number of passengers compared to public transport. The availability of more private vehicles with less number of people gives rise to the problem of traffic congestion thus creating a requirement for an efficient public transport system. Hence, the authors aim to present how modern-day IT advancements could be used to deliver a quality bus transportation experience to Sri Lankan passengers. First, the challenges experienced by passengers were investigated where, heavy traffic, long travel time, overcrowded buses, not receiving the correct amount of balance money and the inability to track the location of the bus beforehand were found to be the most common challenges experienced by passengers. Once, the issues and the corresponding needs were identified, the authors explored the different roles of IT in public bus transport and proposed four feasible solutions to overcome the prevalent issues. The recommended solutions consisted of a bus tracking cum arrival time prediction system that uses GPS and GSM, a bus crowd monitoring system that uses IR sensors, a cashless ticketing mechanism that uses the Touch travel card introduced by Dialog and an inquiry cum complaint management system that would facilitate real time complaint handling and management. Furthermore, the research also introduced a digital transformation framework that could be used to digitalize the operations of public bus transport. The digital transformation of Sri Lanka’s public bus transport system would result in the delivery of a quality transportation experience to passengers while minimizing traffic congestion in Colombo as the availability of a high-quality bus transport service would encourage citizens to use public transport more often instead of their own private vehicles. The proposed research contrasts with other researches as it facilitates the development of a Digitized National framework that would be applicable to the entire bus transport system of the country. Furthermore, it would be beneficial if the passengers are provided with an integrated up-to-date solution where information such as the location of the bus, arrival time, bus fare, duration and journey distance is available in real-time. Besides, the study is also significant as this area has not been much focused academically in the Sri Lankan context. The Ministry of Transport and Civil Aviation, National Transport Commission (NTC), Sri Lanka Transport Board (SLTB) and Sri Lanka Private Bus Owners Association will be the main organizations benefitted by this research in addition to passengers travelling in and out of Colombo.

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