Transport Research Forum

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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
Alternative fare policy for public bus transport in Sri Lanka
(Transportation Engineering Group, Department of Civil Engineering, University of Moratuwa, 2023-12-08) Tennakoon, A; Sharic, S; Bandara, S; Jayantha, WRAN
An efficient, reliable, and cost-effective public transport service plays a vital role in the development of the country’s economy in many ways. According to National Transport Statistics, bus transport services contributed about 35% of the daily need for transportation in 2019. An affordable bus fare is an influential factor in attracting more passengers to public bus transportation in Sri Lanka. Simultaneously, the fare policies should be capable enough to optimise the revenue of the transport operators to preserve a reliable service. The Sri Lankan bus transportation service is currently practising the distance-based fare policy. The fare increases are calculated based on the percentage increase in the weighted average of the vehicle operating costs of ten route categories. However, obtaining the weighted average would not reflect the actual scenarios for such different routes. The existing method calculates vehicle operation cost based on twelve cost components such as fuel cost, crew cost, service, and lubricant cost, tires and tubes, air conditioner maintenance and overhaul, repairs, daily overheads, monthly overheads, annual overheads, depreciation, financing, and provision for risk. These cost components have not been revisited for an extended period. In addition, no consideration of the fixed and variable cost aspects in the calculations can result in less accuracy of the vehicle operating costs. The current fare for air-conditioned service is relatively higher than the normal fare. The frequent variations in fuel costs result in changes in operation costs causing frequent fare revisions. Hence, the operators receive criticism from the passengers about the clarity of the fare revisions as well as the fare levels of the air-conditioned service. Also, no clear mechanism is adopted in the current fare structure to identify and accommodate the transfer costs. Thus, this research attempts to establish an alternative bus fare model for operators and passengers to overcome such issues. It is proposed to calculate the operation costs based on the fixed and variable cost aspects, which realistically reflect changes in the variable operating costs of an operator while maintaining the correct fixed costs for the operation. The twelve existing cost components are reviewed and revised. The revised cost components are categorized into administrative costs, operation and maintenance costs, and finance costs. The expected profit margin is separately identified for each cost component to distinguish the profitability of the bus operators. Also, a simplified fare revision mechanism is introduced to calculate the fare revisions during frequent changes in fuel costs, consumer price indexes, wage levels, and bank interest rates depending on the weights of each parameter to the cost components. The bus routes are classified into seven different services, such as urban, suburban, rural, hill country, and long distance, as per the operation costs. The different fare strategies are determined for each service type to maximise the operators' profitability while minimising the fares for passengers and any transfer penalty. Notably, the air-conditioned service is treated as a separate category, further classified into medium-distance, long-distance, and hill country routes based on operational cost variances. This refinement anticipates a significant fare reduction for air-conditioned services compared to the current structure. In conclusion, this research offers a comprehensive and adaptable fare model that not only ensures the economic viability of bus operators but also prioritizes affordability and clarity for passengers.
item: Conference-Abstract
Analysis of air void variations in hot mix asphalt wearing course mixtures used in Sri Lankan roads
(Department of Civil Engineering, University of Moratuwa., 2015-08) Lakmal, KHR; Mampearachchi, WK; Pasindu, HR
Over the past decades, the road construction with hot mix asphalt (HMA) has been increased significantly. However there were many concerns of the durability of the recently constructed asphalt concrete roads. Therefore, impotency of introduction of new quality control measures is arisen these days. The properties of the asphalt mixture as well as the construction practices are also important for the quality and the durability of asphalt pavements. The present Sri Lankan practice is measure and control of (1) Thickness, (2) Density, (3) Bitumen Content and Aggregate gradation and (4) Roughness Index (IRI) of the laid asphalt mat. The objective of this research is to find out the impotency of measuring the air void of the laid asphalt mat and the need of a combined index of the important parameters to improve the quality and durability of asphalt concrete roads. Core samples were tested at 12 locations with various initial compaction levels at two aging levels, 100 days and 225 days. In addition performance was evaluated of the road sections with various levels of initial compaction after 5 years to check the long term aging of asphalt concrete. It was found that initial air void content significantly decreased under traffic in a short period and long term performance of HMA roads cannot be evaluated by initial air void content alone.
item: Conference-Abstract
Analysis of defects liability period for different type of defects identified in road construction projects
(Department of Civil Engineering, University of Moratuwa, 2018-08) Chathuranga, WAH; Pasindu, HR; Pasindu, HR
In any type of construction work there is a possibility for defects. Defects in road construction can be of many categories: road surface defects, base or sub base defects, drainage issues, design failures or construction failures. Failures can be identified using many methods. Visual observation, accident analysis, public complaints, re-testing etc are among the most common ways of identifying these defects. To minimize these construction defects, in the construction field, contractors have to use high quality materials, better construction techniques and proper machinery. Competitiveness in the construction field leads contractors to try and win the bids by bidding at a low cost. After the lowest bidder is awarded the contract, he tries to generate profits within their budget. Because of this, the contractor might tend to use low quality materials, poor construction techniques and improper machinery to make profit. To mitigate such situations and defend the client against poor construction works, the construction industry has the Defects Liability Period. Defects liability period is a set period of time after a construction project has been completed, during which a contractor has the right to return to the site to remedy defects. A typical defects liability period lasts for 12 months. However different types of defects appear after different time periods from the completion of the road construction. In common practice, Sri Lanka has one year defects liability period for all the defects in road construction projects. However, some defects may occur after one year, so contractors tend to use of low quality materials and poor supervision in road construction. Therefore employers should give carefully consider the wording and requirements of the defects rectification provisions. Where the client considers hiring another contractor to fix the original contractor's mistakes it will lead to the cost a considerable amount for the rectification of these defects. Therefore the analysing of the defects liability period for different type of defects is very much needed in road construction projects. In the recent past many roads have been re-constructed all over the country. These works were carried out by different types of contractors using different types of method statements and methodologies. Most of these contracts have had one year defects liability period. It creates many problems to relevant authorities, even though road surfaces were black top. Also few road construction projects entertain performance based contracts; such a type of contract contractor should maintain the rehabilitated road section for an agreed time period. These types of project rates of bidding items are too high compared to the normal contracts. This cost, sometimes cannot be bared. This may lead to the completion of the project far before their schedule scope due to the unavailability of funds. But most of the developing countries, including our neighbour India, focus on increasing this Defects Liability Period according to the type of defects. This study is an attempt to analyse the defects identification period in road construction, and thereby enabling the proposal of a systematic defects liability period for road construction projects. Absence of a proper defects liability period for road construction causes inconvenience to both contractors and clients. Therefore identification of the DLP would minimize imbalances and inefficiency in the construction industry. The first step is to identify the variants of defects identification. The second step is to analyse different defects with the time of identification. Road construction projects are a major variant and ten different defects components have been identified: such as road surface, base failures, sub base failures, subgrade failures, low quality materials, drainage issues, design failures, construction failures, road marking and signalling issues. To identify those defects a questionnaire survey was conducted within the Executive Engineers’ division in Kalutara District of Road Development Authority. This sample space includes three EE divisions, Kalutara, Agalawatta and Horana. Within these three EE divisions, a 450 km of national highways were maintained. In the last decade 90 percent of the road lengths were upgraded to black tops, in these divisions. Based on the results of the questionnaire, survey charts were developed for these defects, against their occurrence. This will help to identify the DLP for different type of defects in the road construction.
item: Conference-Abstract
Analysis of factors affecting pedestrian route choice
(Department of Civil Engineering, University of Moratuwa., 2013-07) Hewawasam, C; Bandara, JMSJ; Wirasinghe, CS; Pasindu, HR
Walking is considered as a most efficient mode of transport for shorter distances as it is environmentally friendly, requires minimal energy, costs nothing and is accessible to all irrespective of the age, gender and ability if facilities are provided appropriately. Pedestrian facilities in an urban area have a significant influence on the traffic flow and socio-economic environment. Communities with good pedestrian facilities will enhance the quality of life. Pedestrians enjoy a high degree of freedom of movement even in a highly congested area as opposed to vehicles. Accordingly, more alternative paths are available for pedestrians between any origin-destination (O-D) pair. This paper describes a study carried out in Panadura city center in Sri Lanka to estimate the relative importance given by pedestrians to various factors such as travel time and visual attractions in their route choice. The first part of the questionnaire that was used in the study was on their current journey and the second part was based on stated preference using a series of hypothetical route choice questions. Here respondents were presented with choices between hypothetical yet realistic alternatives, with each alternative being described in terms of their attributes. The results were obtained by conjoint analysis and highlighted that travel time is the most significant factor in route choice for less than 1000m trips and travel distance got priority for longer distance trips. Further, it is apparent that congestion and visual attractions were secondary factors their route choice.
item: Conference-Abstract
Analysis of optimal expansion level of a single runway airport
(Department of Civil Engineering, University of Moratuwa, 2022-12) Siriwardena, S; Perera, L; Perera, HLK
Air travel is rapidly increasing all over the world, and airport capacities are crucial when serving this growing demand. When it comes to airport capacity, whether it is passenger or freight, runway capacity is the key determining factor among many others. At the same time, adding a runway to existing airports is an expensive process, from the design itself to obtaining approvals, construction, and completion, compared to any other developments associated with an airport, such as passenger areas and other service areas. However, despite the cost and other negative external factors involved, most airport authorities tend to make a bold decision to add another runway to the existing Airport without looking at optimizing existing and future operations. This appears to be the case for Bandaranaike International Airport (BIA), which made plans to build a second new runway to accommodate future traffic. Therefore, the main aim of this research is to identify how to achieve the optimal expansion of a single-runway airport without adding a second runway. This is achieved by identifying critical parameters that affect runway capacity and analyzing ways to obtain the optimal capacity. Hence, the next appropriate solution to accommodate future traffic growth is to optimize current operations rather than physical expansion due to drawbacks such as high capital costs, long implementation times, community opposition, and so on. After collecting the necessary data, an analysis was carried out to determine the current capacity and the utilization of the runway at BIA. From the analysis, it was found that during a peak period, more than 50% of runway capacity is idle, meaning that it's been underutilized heavily at present. In other words, BIA can simply double the operations with the existing runway, and now the question is whether BIA expects a growth rate greater than this within the next 15-20 years. There are ways to optimize runaway capacities in addition to determining the truly available runaway capacity. One such option would be to assist air crafts in evacuating from the runaway in the shortest possible time without any hindrance to RADAR and wake turbulence separations so that they can conduct the next operations. This was found to be the next largest bottleneck hindering runaway capacity, and as a result, the implementation of high-speed exits has been considered in this study using the REDIM software. In addition, the best departure and arrival sequences were discovered using Python code to utilize the time more efficiently, as runway occupancy time (ROT) differs according to the aircraft category. It can be concluded that the existing runway capacity could be further improved by optimizing the current operations, as ROT was reduced by 10%. ROT reduction leads to a reduction in costs and delays, which would make a significant difference during peak hours. As the world's busiest Airport that operates with a single runway, Mumbai airport handles aircraft at 65-second intervals, and it's important that optimization strategies are implemented at such airports to avoid significant delays.
item: Conference-Abstract
Analysis of road accidents in “A9” roads in the Northern Province
(Department of Civil Engineering, University of Moratuwa., 2018-08) Munas, MMM; Bandara, JMSJ; Pasindu, HR
A9 (Kandy-Jaffna Highway) is the most popular road in Sri Lanka, and was opened for traffic after the renovation of the section from Vavuniya to Jaffna, in 2013. Even though several safety precautions have been provided, most number of accidents reported along the highway have occurred in the district of Jaffna, Kilinochchi and Vavuniya. Therefore, identifying locations that may lead to accidents, the cause for the accidents, and where majority of the accidents take place are essential, for immediate safety measures and improvements. The main research objectives are to identify accident prone locations, identify possible reasons for the accidents and calculate the accident rate based on vehicle travel kilometre. According to this research, fifteen most critical accident-prone locations were identified in the A9 road section from Vavuniya to Jaffna. Accident locations were grouped into the nearest 100m distance, and the fifteen most critical locations are 171+100km, 176+100km, 177+100km, 180+200km, 183+200km, 212+800km, 252+100km, 299+100km, 300+100km, 302+100km, 303+100km, 305+100km, 309+100km, 311+100km and 312+200km. Main causes of the accidents, as per the accident records, are the driving speed and the poor road environment(light condition). Driver fatigue also acted as a key factor for some accidents. Accidents that happened during day time were twice as higher than that of the night time in some locations while some were equal. However, this trend was the same in each section along the road. The highest accident rate that was around 1.31 x 10-6 veh km, was noted from Palai to Meesalai east section. Accident rates in each section have increased from year 2012 to 2014. When comparing A9 road section from Vavuniya to Jaffna with A9 road section from Kandy to Vavuniya with the same corridor geometry in 2014, A9 road section from Vavuniya to Jaffna shows a higher accident rate (0.68 x 10-6 per vehicle kilometre travelled) than other corridors (0.47 x 10-6 per vehicle kilometre travelled). In addition, fatality rate in A9 road section from Vavuniya to Jaffna has increased from 2012 to 2014, which is considerably a higher value than the fatality rates of road accidents in most of the other countries.
item: Conference-Abstract
Analysis of suitability of dry-back process in Sri Lankan road pavement construction
(Department of Civil Engineering, University of Moratuwa, 2022-12) Vasavan, V; Mampearachchi, W; Perera, HLK
Moisture content is an important component in the Compaction of pavement layers in road construction. Moisture content in pavement layers is varied by precipitation and environmental factors in the construction and operational stages. If the measured moisture content of the pavement layers exceeds the optimum moisture content, it causes premature pavement failures, such as traffic compaction in the wheel path. Also, this excess moisture content leads to the formation of undulation in the pavement. Therefore, the Dry-back process is widely used in Australia and New Zealand to prevent such pavement failures. The dry-back process is required to prevent the pavement from moisture-related failures. Water is added to the pavement material to achieve a specified density in the construction stage. If the moisture content of the pavement layer exceeds the optimum moisture content, pavement material must be allowed to dry to a certain level below the optimum moisture content. It is known as the dry-back process. Before laying one pavement layer over the other, the water content of the laid pavement must be checked. This is the quality measurement activity for the dry-back process. This research mainly focuses on the dry-back Requirement in Sri Lankan Road pavement construction. The research was carried out using four methods such as survey, material comparison, case study, and practical analysis. First, based on carried out industrial surveys, it was found that the dry-back method is followed in Sri Lankan pavement construction practices without understanding the exact process of it. Second material comparison, In Australia, higher quality materials are allowed for pavement construction when compared with the Sri Lankan Standards. In Australia, field compaction is maintained at a higher value, whereas California Bearing Ratio (CBR) is kept lower than the Sri Lankan materials specification. Various testing methods are practised in Australian Construction processes to ensure the quality of materials compared to Sri Lanka. The third Case study, weather reports, and testing summaries were interpreted to identify the pavement layers with high moisture content, specifically during the rainy season. On the other hand, failures on the pavement surface were identified. Professionals were interviewed regarding these pavement failures, while weather reports and material testing-related data were analyzed. Both approaches clearly illustrate that high moisture content might increase the possibilities of reconstruction of layers, obstruction in the pavement compaction, and pavement failures. Further, this finally practical analysis was carried out in the road sections where cracks are formed on pavements due to moisture content above the optimum moisture content. The moisture content of the pavement layer should be below 60% degree of saturation is preferable for the Sri Lankan pavement condition. This condition is derived from the literature survey and practical analysis of this research. Hence it can be concluded that the dry-back process is a primary requirement in Sri Lankan Road pavement construction.
item: Conference-Abstract
Analysis of the flexible pavement sections using mechanistic - empirical method
(Department of Civil Engineering, University of Moratuwa., 2013-08) Mampearachchi, WK; Dulwala, NP; Pasindu, HR
Pavement design procedures used in road design is either empirical or mechanistic. In Sri-Lanka most of the road pavements have been designed based on the empirical design methodologies. A guide to the structural design of roads under Sri Lankan conditions issued by Road Development Authority (RDA) is used as the reference for the local road pavement designs. Overseas Road Note 31 and American Association of State Highway Transportation official’s method (AASHTO) are the other references used in the pavement designs. Pavement layer compositions given for the same road section by the different references are not in the same. In the other hand due to the non- availability of the materials and different cost constraints in the projects might subjected to change the pavement compositions rather given by the design references. So the different layer compositions are needed to be analyzed against their performances and developing improving method for analyzing is required. The quality of material properties in different layer composition can be evaluated through the mechanistic- empirical methods. KENLAYER is the mechanistic- empirical tool widely used in the pavement analysis. The output results of the KENLAYER gives the vertical stresses and strains, horizontal stresses and strains, and displacements at the specified locations. For the selected road stretch, traffic data has collected .The same section has designed using different design references and some sections are subjected to changes as available material properties. Some pavement compositions are designed with the same structural adequacy, matching with the structural Number by the varying material property which gives economic benefits. These different pavement compositions are used in analysis. Design life has analyzed for the each pavement composition using Mechanical – Empirical method. The critical layers are identified at early stage of the failure. The study concludes by identifying the best suitable pavement composition by the evaluating of the pavement performance.
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 design standards of bus terminals in Sri Lanka
(Department of Civil Engineering, University of Moratuwa, 2021-10) Medawatte, V; Sirisoma, N; Perera, HLK
Transportation has become a major component in a countries’ development. Improvement of public transportation along with their infrastructure is a timely need to address its demand. The comfort, safety, and attractiveness of a public transport mode should be ensured in order to promote it among citizens. Buses are one of the main public transport modes in Sri Lanka, which has accessibility to a wider area of the country. In order to attract more people to utilize buses, passengers should be offered with necessary services. Bus terminal is a main component of bus transport network, where bus trips are generated or halted. These bus terminals are utilized by a massive number of passengers daily. Therefore, infrastructure should be developed at these stations under proper standards in order to ensure the quality of service provided. However, the existing terminals are unable to fulfill the basic amenities required by passengers and are not sufficiently designed to ensure comfortable movements inside the terminal. Many passenger-bus conflicts, bus-bus conflicts are commonly experienced in terminals. Entry and exit points creates negative traffic impacts at terminal locations. The main reason for this is the absence of a proper set of guidelines that can be referred to, when constructing bus terminal structures and infrastructure. Currently a set of design standards to be reffered for a bus terminal design within the Sri Lankan context does not exist. The main objective of this study is to introduce systematic bus terminal design guidelines ensuring the supply of complete infrastructure facilities needed for bus passengers. Western Province has been selected as the study area for this research. Western province bus route data is obtained from National Transport Commission (NTC), Western Province Passenger Transport Authority (WPPTA), and Sri Lanka Transport Board (SLTB). The origins and destinations of the bus route data were used to identify the bus terminals within the study area due to the absence of a centralized database. The basic features of these identified bus terminals such as total number of bus routes generated, number of long-distance and short-distance bus routes, number of A/C and non-A/C bus routes generated, and the availability of multimodal facility was obtained by classifying the collected data. A total of 44 bus terminals were recognized within Western Province, disregarding the terminals which generate less than 5 bus routes. A terminal classification was developed considering the nature of the identified bus terminals. The terminals were categorized into four main categories namely Category A, B, C and D. Along with the above classification, a terminal ID was developed considering the basic features identified for terminal classification along with its location details. A questionnaire survey was carried out with a total sample size of 300 respondents distributed among bus passengers and bus terminal staff covering 3 bus terminals from each category (12 bus terminals). The objective of the questionnaire survey was to identify the passenger requirements and the standards of the existing terminal facilities. The passengers’ tendency to use these facilities while traveling and additional facility requirements apart from the available were taken into consideration. Literature related to existing bus terminal guidelines in other countries and the design standards currently used by architects for terminal construction in Sri Lanka were referred. The features of the Sri Lankan bus transport network, such as types of 32 buses and passenger behaviors were taken into consideration. Based on the research finding a guide book was developed to be used in Sri Lankan bus designs. It includes a set of design guidelines are submitted for the drafting of bus terminal designs under several sections. Basic building construction guidelines, layout factors such as bus bays, turning radii, parking requirements, pedestrian space requirements, passenger amenities such as seating requirements, queue lines, terminal staff requirements, information, signages, demand of differently-abled passengers and safety standards were taken into consideration. This code of guidelines would be beneficial as there are no proper designing instructions for bus terminals available for the Sri Lankan context at present. Other than that, certain functional requirements for bus terminals are separately identified as mandatory and optional requirements according to the terminal categories. It would prevent the over-allocation of resources in construction of terminals based on the terminal category. This study recommends to follow the guidelines presented in constructing new terminals considering the features of the terminal facilities. It can also be referred to prioritize the facilities to be addressed in the refurbishment of existing terminals.
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
Analysis on transport mode choices of school children in Colombo District, Sri Lanka
(Department of Civil Engineering, University of Moratuwa, 2020-12) Damsara, P; De Silva, D; Sirisoma, N; Perera, HLK
The increase in the usage of private transport modes for school trips has become a major reason for traffic congestion in Colombo District during peak hours. Colombo District consists of 402 functioning government schools, with a total student population of 374,995. Those schools have been categorized into four categories based on the availability of classrooms. According to the Ministry of Education, there is a limitation which is imposed on the distance from home to school, in the student enrollment process. However, it has been identified that the distances are exceeding the limitation, with respect to the school type and location. As a result, students choose different transport modes based on many factors such as accessibility, connectivity, safety, reliability and comfort. This study focuses on identifying the distances from home to school and the respective transport mode choice of the students in Colombo District. In addition, the factors which affect those school children to avoid public transport modes were analyzed. The quantitative research approach has been used in developing the research methodology in several phases such as factor identification, mode choices and demand distribution. Data collection has been conducted through a questionnaire survey which covers 28 selected schools under four categories, with a total sample size of 2875 in all Divisional Secretariat Divisions (DSDs) of Colombo District. Stratified sampling technique was used to collect data from the above school types. Schools which have classes in all streams up to advanced level (1AB schools) show the highest percentage of students (44%) who travel a distance of 2-10 km from home to school, while other school types show the highest percentage of students (49%) who travel a distance range of less than 2 km. Further, it has been identified that 1AB schools have some students who travel more than 25 km daily for their school trips. School van/bus services are the main mode of transport which is used by the students of schools located in Colombo Municipal Council (CMC) area, while public transport modes such as bus, train and “Sisu-Sariya school bus service” are the main modes of transport which are used by the students outside the CMC area. Active transport modes are the least popular mode of travel in both CMC and Non-CMC area (13% each), while private transport modes, which consists of car/van/jeep, motorbikes and three-wheelers contribute 25% in CMC area and 33% in Non-CMC area. Furthermore, it has been identified that longer travel times, longer waiting times, poor accessibility, less security and less comfort are the main reasons for the students in Colombo District, to not use public transport services. Even though there is a dedicated public transport service (“Sisu-Sariya”), which have been provided for school children, it has been found that there is a considerable usage of private transport modes for school trips in the district. Therefore, this study recommends a procedure to develop an improved public transport system for school trips including a model for trip distribution patterns, network connectivity and system planning to attract more students into public transport services.
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Animal collision induced road accidents in the Southern Expressway
(Department of Civil Engineering, University of Moratuwa., 2014-08) Mayadunnage, S; Colombage, SS; Weerakoon, DK; Mampearachchi, WK; Pasindu, HR
Declaring open the Southern expressway in November 2011 marks a major milestone of the future road network development in Sri Lanka. Ensuring road safety is one of the key considerations during the operational phase of an expressway as vehicles travel at a much faster rate, which will increase the probability of road accidents. During the period, November 2011 to December 2013, 1023 road accidents have taken place in the Southern Expressway. Out of these, 20% have resulted due to animal-vehicle collision. Animal-vehicle collisions could result in property damage, personal injury or fatalities to the commuter. This study was undertaken to analyze temporal and spatial patterns of animal induced road accidents reported in the southern expressway that would inform development of mitigation measures to reduce the incidence of road accidents caused by animal collision. Accident reports available for animal collision related road accidents during the period, December 2011 to December 2013 was collected and analyzed to identify animal collision patterns. During this period 173 road accidents have taken place. Out of these 172 accidents only involved only a single vehicle while one of the incidents involved two vehicles. Further, 98% of the incidents (169) resulted only property damages while the remaining four incidents have resulted in injury to the 10 commuters. During the study period no fatalities have resulted due to accidents due to animal collisions. There was no significant difference between the incidence of road accidents resulting due to animal collisions reported in the Galle bound section (87 incidents) compared to Colombo bound section (86 incidents) of the highway. The rate of accidents resulting due to animal collisions has reduced by 11% during the second year of operation compared to the first year. Animal collision rates fluctuated over time with highs in April and July and lows during March and May. The highest number of incidents was reported in the stretch between 80 and 90 km followed by 21 to 30 km stretch. Out of the 173 accidents recorded, 70% (121 incidents) have resulted due to collision with dogs followed by pigs (20 incidents), birds (20 incidents) monkeys (7 incidents). Out of the 20 accidents reported due to bird collision 13 have resulted due to Peacocks. Other animals that have resulted in accidents include land monitors, buffaloes, goats, porcupines and foxes which have all contributed less than 5% of the incidents. The road accidents resulting due to collision with dogs have undergone a 33% reduction during the second year of operation compared to the first year. Out of the 173 animal collision related road accidents reported 74% involved motor cars followed by vans (11%), jeeps (8%), cabs (5%), busses (1%) and lorries (1%), indicating smaller vehicles are more susceptible for animal collision related road accidents. Out of the reported animal related road accidents 58% have occurred during day time and 87% of these accidents have occurred on sunny days while the rest on rainy days. Further 83% of the animal related road accidents have taken place on clear days compared to 13% that have occurred during rainy days. Therefore, lack of visibility or whether condition may have not contributed to animal related road accidents. This study indicates that animal related road accidents show clear spatial and temporal patterns that can be used to develop mitigation measures in the future.
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Applicability & design requirements of an intelligent pedestrian crossing
(Department of Civil Engineering, University of Moratuwa, 2018-08) Godawita, H; Jayasooriya, N; Bandara, S; Pasindu, HR
Pedestrian crossing is one of the places where pedestrians and vehicles interact each other. This interaction often causes delays to both pedestrians and vehicles and increase possibility of accidents between vehicle-pedestrian and vehicle-vehicle. In order to manage these interactions, controlling mechanisms such as traffic signals are used. This research looks into the possibilities of making these interactions safe and less delay causing to both pedestrians and vehicles, by means of appropriate controlling mechanisms with the help of present technical capabilities. The objective of this research is to come up with a design guideline for an intelligent pedestrian crossing and to compare its effect on minimizing delays and reducing risk of accidents as compared to standard zebra or signalized pedestrian crossing. Only the isolated pedestrian crossings are considered for this study. End purpose of the research is to identify the applicability of intelligent pedestrian crossings and to identify design requirements for an intelligent pedestrian crossing at places where it is needed. Design requirements are characterized based on four main parameters; vehicle flow, vehicle speed, pedestrian flow and safe stopping distance for vehicles. The proposed design requirements allow intelligent pedestrian crossing to decide to whom to give the priority based on traffic & pedestrian flow condition and the location of pedestrian crossing. Main findings of the research include identification of different design requirements; signal operation strategies for different traffic conditions and analytical solutions to identify appropriate timing requirement of the traffic signal. Four different situations based on pedestrian flow and vehicle flow have been analysed. Intelligent pedestrian crossing will be suitable for all except the situation where both pedestrian and vehicle flows are high. It is proposed to vary amber time considering whether a vehicle can be safely stopped or whether it is allowed to pass through the pedestrian crossing. The decision is based on the approaching speed of the vehicle and its safe stopping distance. Red time and Green time could vary depending on the crossing ability (speed) of pedestrian and the crossing length.
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Applicability and effectiveness of the park and ride system for Kandy City
(Department of Civil Engineering, University of Moratuwa., 2016-08) Karunadasa, JMAI; Pasindu, HR; Pasindu, HR
Kandy is the main city in Kandy District and Central Province. As a result of increased car ownership with increase of income level among other reasons, modal share of public transport has decreased over the years. This will increase congestion of roads, reduction of mobility and reliability. One possible option is to reduce the private vehicle users to public transport modes or combination of both private vehicles with public transport mode. “Kandy City Transport Study, (KCTS)” and “Kandy Transport Improvement Program, (KTIP)” have proposed strategic plans to improve transportation system in Kandy city. Furthermore three Satellite Stations were proposed at Getambe, Katugasthota and Thennakumbura with Kandy Multimodal Transport Terminal. In this research, applicability and effectiveness of the park and ride system to Kandy city was studied. Based on available traffic data, number of private vehicles entering to Kandy city in the year 2018 was forecasted in main links. Recent studies found that 59.5% of passenger vehicles‟ trips end are in Kandy CBD. Willingness to use of park and ride system among private vehicle users were assessed through questionnaire. Questionnaire was mainly focused on traveler‟s background information, travel behavior data, satisfaction of present transport mode and important factors for better Park and Ride system. Trip information data and other information given by the responders were analyzed through the statistical methods. Finally acceptability of the proposed Park and Ride system was analyzed with monthly income level, average travel time, average trip length, expected waiting time on average journey and average walking distance from point of egress from the public transport mode. According to the results, acceptability of the proposed Park and Ride system mainly depends on average walking distance from the point of egress from the public transport mode to destination, monthly income level and waiting time on an average journey. The effect of Travel time and Average trip length has not strong correlation with acceptability of the proposed Park and Ride system. Most responders were not satisfied with the current travel time, pedestrian walkways and satisfactory level of bus stands, bus halts, railway stations and halts. Responders are expecting reliable and comfortable public transport system with high frequency for successful proposed Park and Ride system in Kandy city.
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Applicability of HCM 2000 & 1986 to determine the level of service in urban arterial roads, Sri Lanka
(Department of Civil Engineering, University of Moratuwa., 2012-07) Mampearachchi, WK; Jayasuriya, WWC; Senaratne, SAMANI; Sumanathissa, RPP; Pasindu, HR
The objective of this research is to identify the applicability of Highway Capacity Manual (HCM)to determine the Level of service in urban minor arterial roads in Sri Lanka. HCM has been developed by the transport research board, USA. Currently most of the local road development agencies use HCM for capacity analysis of roads. There have been no researches carried out to identify the applicability of HCM to the Sri Lankan condition. To depict the quality of service of the roads quantitative measures of a traffic stream are required. Level of Service (LOS) is a quality measure describing operational conditions within a traffic stream, generally in terms of service measures such as speed and travel time, freedom to maneuver, traffic interruptions and comfort. Six LOS are defined based on service flow rates of roads. Letters designate each level from A to F with LOS A representing the best operating conditions and LOS F the worst. Though the local roads have acceptable LOS, the results obtained from both HCM 2000 and1986 have not reflected it. It is required to identify the factors which affect the LOS. For that a sample of two way - two lane roads were selected. For the selected sample flowvs.density curveshave been developed by considering traffic data and speed survey data. Based on the literature findings and data collected from the field, six LOS for the urban minor arterial roads have been defined.
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Applicability of rational formula for larger size catchments in highway drainage design
(Department of Civil Engineering, University of Moratuwa., 2015-08) Dissanayake, GA; Pasindu, HR; Pasindu, HR
The rational formula has been used for the peak flow estimation over 150 years and still remains as the most widely used flood estimation technique. The method is applied assuming that rainfall intensity and storm duration is uniform over the study area; storm duration is equal to the time of concentration of the catchment; and the runoff coefficient is constant during a storm. The assignment of precise upper limit on the catchment area for reliable application of rational method varies from country to country and among literatures. As many literatures indicated, it has been specified that rational method is appropriate for small catchments. However, the definition of small catchment is not consistent across practitioners. The peak flow estimation of drainage structures would be a vital design consideration in evaluating the capacity adequacy of existing drainage system and to propose extension/new addition to the present drainage system, if it failed to satisfy the anticipated peak flow of a structure. The hydrologic model determines the runoff that occurs following a particular rainfall event. The primary output from the hydrologic model is quantity, rate and timing of stream flow that results from rainfall events. The Hydrologic Modeling System (HEC-HMS) originally developed by the U.S. Army Corps of Engineers is used to simulate precipitation-runoff processes of dendritic watershed systems. It includes many of the well-known and wellapplicable hydrologic methods to simulate rainfall-runoff processes in river basins. The study focuses on the hydrologic design of cross drainage structures of road sections located in different hydrological and geographical zones in Sri Lanka. The topographic maps of 1:10,000 and 1:50,000 together with google terrain maps were used to identify the respective catchment areas and catchment characteristics. The peak flow corresponds to return periods of 25,50 and 100 years determined by the rational formula and comparison of these values with the outputs derived through HEC – HMS model were then used for the determination of upper limit of the catchment area where the rational formula can be applied.
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Applicability of standard density in QC and QA of asphalt surfacing
(Department of Civil Engineering, University of Moratuwa, 2021-10) Rathnasiri, P; Mampearachchi, WK; Perera, HLK
The significance of quality control and quality assurance at the compaction operation in the asphalt pavement has long been recognized by the industry since the compaction maintains the volume of air in the asphalt, which has a profound effect on pavement performance and pavement service life. As a compaction quality control parameter, the degree of compaction, expressed as a percentage ratio between field density and the reference density, is used in the pavement industry. There are several methodologies to establish the reference density to formulate the degree of compaction in the present. However, for decades, measuring densities from daily laboratory compacted samples during construction (Marshall Density) has been the mainstream practice to establish the reference density in Sri Lanka. The major drawback of establishing Marshall laboratory density as a reference density is its inability to represent any unnoticed material or plant variations in the field. This study focuses on solving the aforementioned constraint by developing a new systematic approach called the ‘Standard density method’ to establish the reference density. The standard density is determined as the mean value of densities of Marshal test specimens from morning and evening operations only for a specified number of days after the commencement of construction. This study aims to evaluate the feasibility of the concept of standard density method by comparing current practice with the proposed method. In-place density readings and their respective Marshall laboratory density measurements were collected from different road projects, and the compaction performance was evaluated according to the degree of compaction (at least 97 percent of reference density) in both the existing and proposed methods. To increase the reliability of this comparison, method comparison hypothesis testing (student t-test) was developed for both the existing method and the proposed method to analyze the compaction performance. This t-test was designed to support the alternative hypothesis ‘in-place density > 97% of reference density (from Marshall density & standard density)’. According to hypothesis test results, the analysis reveals a significant correlation in compaction rates between the current and proposed methods (significant at a 5% level of significance). Moreover, the study shows that the hypothesis mentioned above can be rejected only in the standard density method if any material or plant variations have occurred in the project; in addition, these hypothesis rejections appear after a considerable time period from the commencement of the construction.
item: Conference-Abstract
Application of data science technologies to take proactive decisions to control road crashes
(Department of Civil Engineering, University of Moratuwa, 2021-10) De Silva, I; Perera, L; Perera, HLK
Traditionally, road traffic crash analysis and accident modeling resorted to regression models and discrete choice models. Many countermeasures have been identified and implemented but still, the number of crashes and severities are increasing every year. Since road traffic crashes occur across space and time, conventional approaches have failed to provide alerts and insights in relation to geospatial regions, enabling proactive prevention measures. Aggregation of other data sources such as real-time weather, traffic flow counts and congestion levels etc. to alert authorities on increased crash risks is another gap that needs attention. The lack of geospatial analysis or visualization on available crash data (e.g., crash hotspots identification) limits road agencies' abilities in prioritizing funds allocation to more impactful improvements. The enforcement authorities also find it difficult to deploy their staff strength to high-risk areas. The latest advancements in programmatic geospatial analysis, interactive map visualizations and open-source software offer a unique opportunity to fill these gaps in a cost-effective way. This paper presents an application of data science and data visualization technologies to analyze road crashes. Popular packages written in Python programming language were used for the analysis. GeoPandas library provided the ability to process GPS locations (latitude and longitude) while Matplotlib was used to generate static maps. Folium library and the underlying Leaflet.js library were applied to generate interactive maps to help visualize crash hot spots. The study developed algorithms to combine GPS location data from crash records with boundary and attributes data from geospatial files to generate road crash density maps by administrative division areas and population. Interactive maps that allow authorities to drill down (or zoom in) to hot spots were also developed. Unlike GUI-driven analysis tools such as ArcGIS or QGis, the programmatic approach developed in this study enables the repeatable application of the analysis and visualization to new and old datasets with minimal effort. The application of existing geospatial analysis tools to road crash data is the key contribution of this study. The findings from the study lay the foundation for a digital system that can become an online platform for road and enforcement agencies to obtain reports and alerts on road crash risks and hot spots. The application was tested using crash data in Sri Lanka and outcomes are presented in this study. Future work such as real-time prediction of crash risk using machine learning technologies and fusion of multiple data sources onto the same platform can bridge the current gaps in crash prevention measures.