TRF - 2016

Permanent URI for this collectionhttp://192.248.9.226/handle/123/17953

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item: Conference-Abstract
Transport Research Forum 2016 (Pre Text)
(Department of Civil Engineering, 2016) Pasindu, HR
item: Conference-Abstract
Sustainable concrete mix design for interlocking concrete block pavers (ICBP)
(Department of Civil Engineering, University of Moratuwa., 2016-08) Hettiarachchi, HACK; Mampearachchi, WK; Pasindu, HR
Heavy usage of cement in modern construction industry has led to numerous environmental problems. The cement industry is one of the main industries which release carbon dioxide, a major greenhouse gas. Raw material extraction to manufacture cement is another major environmental impact. Heavy damage to the limestone deposits on earth when mining is causing major environmental pollution. (Mishra & Siddiqui, 2014) Reduction of cement usage in concrete industry is critical for a sustainable future. Particle packing optimization method can be successfully used to reduce the cement content while maintaining the quality of the concrete. Selecting aggregate proportions to achieve required qualities of concrete is a challenging task. When a unit volume of concrete is considered, this volume consists of aggregates and cement paste. Aggregate form the skeleton of concrete and cement paste will be used fill the voids in between aggregates and coat the aggregate to ensure proper bonding. Packing of aggregate is a main factor for a high quality concrete. Optimization of aggregate is the process of determining the most suitable aggregate particle sizes and distribution to minimize the voids content of an aggregate mix. An optimized aggregate mix will have lesser amount of voids which needs to be filled with cement paste resulting low cement, high quality concrete. Particle packing optimization is the process of selecting optimum aggregate proportions that result in minimum voids and maximum density thus requirement of cement and water can be minimized. Optimization of aggregates to achieve higher strengths with lower cement content has been studied for various applications over the past decade. Theoretical packing models such as Toufar, De Larrad, CPM, LPDM, power curve, Shilstone chart etc. were analyzed to determine the most suitable packing model. Though those studies were successful for more generalized applications there were limitations when applying the results for specialized applications such as zero slump concrete, pre cast concrete products, roller compacted concrete self-compacting concrete, high performance concrete etc. The main reason for such limitations in generalized approach is the variation of the required properties of concrete in each application such as low water content requirement in zero slump concrete, roller compacted concrete and pre cast concrete, high water requirements in self-compacting concrete etc. The concept of particle packing is adopted to determine sustainable concrete mix for interlocking concrete block pavers (ICBP). Typically the aggregates used for the concrete are 12mm coarse aggregates with manufactured sand and natural sand as fine aggregates. Fresh concrete is poured into the mold and both vibration and compaction is applied to cast the block. The mold is removed soon after the block is cast. Hence a low water cement ratio and high green strength needs to prevent edge falling and cracking of freshly cast ICBP. Present industrial practice seems to be far less economical due to the use of high amount of cement, wastage of aggregates, and high energy consumption of machines due to improper mix proportions. The manufacturers use high amount of cement to achieve higher strengths. There are high variations in strength within the same batch of blocks. The main reasons for such variations is the lack of consistency in mixing, segregation of aggregates when pouring concrete mixture to the molds, lack of proper curing practices, not following a proper water/cement ratio as intuition is used to measure the adequate water content etc. Hence high strength variations within the same batch is visible. This study proposes improved sustainable mix design using packing density method by optimization of parameters such as water cement ratio, coarse to fine aggregate ratio, quarry dust to natural sand ratio, cement content and compaction effort. The results of the study shows that the cement content can be reduced by 37% by optimizing the aggregate content used in the concrete mix.
item: Conference-Abstract
Cost effective roughness computation method using smart phones
(Department of Civil Engineering, University of Moratuwa., 2016-08) Gamage, DE; Pasindu, HR; Bandara, JMSJ; Pasindu, HR
Road roughness is a representation of its surface condition and is resulted of the irregularities in the pavement surface such as potholes, depressions, cracking, rutting, ravelling etc. International Roughness Index (IRI) is the globally accepted indicator to measure the road surface condition. The main problem- associated with low volume roads in Sri Lanka is lack of funding for maintenance and resources. Unfortunately in many developing countries like Sri Lanka planning decisions on maintenance are mostly taken based on subjective judgment/ad-hoc decisions without a consistent objective basis due to significant political and other interferences. Fund allocation can be optimized if the decision making can be supported by up to date information of the road network condition. Road Roughness information is very useful for road agencies because it can be used to assess the road condition and be used in decision making process for maintenance planning and programming. In addition, the information is very important for road users because using such information, road users can avoid the bad roads ahead. But existing measurement technologies used in Sri Lanka like Profilometer are very expensive. It also has limitations in accessing narrow roads though it can provide accurate information. Therefore it is necessary to investigate low cost, practical methods to evaluate roughness which can be used in maintainence planning and programming of low volume roads. Today smart phones have the capability of collecting information related to variation in road surface level which can be converted to road roughness measured as IRI (International Roughness Index). - number of smart phone applications are available but it is necessary to calibrate such models to suit local condition and vehicle used for data collection. The results of these can be considered as adequate for comparison of relative levels of road roughness which will be useful for maintainence decision making In this research regression analysis was used to - find a relationship between roughness value (IRI) obtained from profilometer and resultant accleration obtained from an android application called Androsensor. Engineers can use that relationship to estimate road surface condition based on accelerometer readings. It can be expected to have more than 60% savings by using this smart phone application for roughness computation of roads.
item: Conference-Abstract
Improvement of coastal sandy soil by blending the local Uoori clay for subgrade/embankment and sub base construction: experimental study
(Department of Civil Engineering, University of Moratuwa., 2016-08) Kowsikan, K; Mampearachchi, WK; Pasindu, HR
The major part of the Northern Province is surrounded by sea and the mainland is connected by several lagoons. The terrain of the province is almost flat and of low elevation. The road development activities in the coastal line of the province has been intensified in the recent past to provide access to the community and other infrastructure development. Formation of coastal road network is emphasized to achieve socio economic benefits to the community. However scarcity of locally available road construction materials hinders the road development badly and causes heavy transport costs involving long haul distance. The borrowing of materials from outstations also leads to social and environmental issues. Usually a traditional method is used for road formation/construction in the coastal areas, by placing the Palmyra leaves to reinforce the subgrade with adequate cover of locally available Uoori clay. However above construction method had shown signs of failure within a short period despite low traffic on the road due to Non- blending of materials by mechanical means and placing the clay with improper moisture content and uneven layer thickness. It is prudent to explore the use of locally available materials with improvement of its quality with suitable stabilization technique. The coastal sandy soil and local Uoori clay are freely available in bulk in the coastal areas. Research on these materials were conducted to determine its properties under different compositions to meet the specification limit of the “Standard Specifications for Construction and Maintenance of Roads and Bridges (SSCM) (ICTAD, 2009)" in Sri Lanka. Testing for Sieve Analysis, Atterberg Limits, Modified Proctor and California Bearing ratio (CBR) were performed for different composition 50:50, 60:40, 70:30, 80:20, 90:10 and 100:00 of Uoori clay and coastal sand. Initial dry sieve and wet sieve tests were conducted for composite material before compaction to determine the clay influenced by Uoori. The results shows the percentage of passing 0.075μm sieve is less than 1.20% for dry test and the percentage passing through 0.075μm varies from 14.7% to 32.6% for wet test depend on the percentage of Uoori clay resulting higher passing percentage for samples with high amount of Uoori clay. The Liquid Limit (LL) and Plasticity Index (PI) were computed for samples collected from initial composite material before proctor compaction and samples collected from optimum compaction level under laboratory conditions ( MDD at OMC) to examine the influence of Uoori particles. The test results for two methods have shown the significant increment of limit results for each composite material due to the fraction of Uoori and escape of clay through 0.425μm sieve. The composite material 60:40 has satisfied the specification limits of sub base material for road construction even the limit variation for LL and PI from 32.20 to 36.90 and 6.59 to 11.11 respectively. The Modified Proctor were performed for composite material to determine the maximum dry density (MDD) with corresponding optimum moisture level (OMC). The results showed that the composite material have satisfied the specification limits. CBR tests were conducted to examine the bearing strength of the composite material under four day soaked condition and test results have shown that the composite material 60:40 satisfied the specification requirement for sub base. The above mentioned tests results for composite material 60:40 indicate acceptable specification limits except the initial test results of sieve analysis. Therefore, sieve analysis was conducted for specified composite material 60:40, where the sample was selected after the proctor compaction at MDD. In addition to that the behavior of the composite material 60:40 was evaluated by analyzing the particle fraction with increment of compaction effort to study the field condition.
item: Conference-Abstract
Development of expanded clay as internally curing concrete aggregate
(Department of Civil Engineering, University of Moratuwa., 2016-08) Bandara, MMHW; Mampearachchi, WK; Pasindu, HR
The increase of highway and other related structures development of any country due to economic boom may lead to introduce fast and sustainable construction techniques and materials. Internal curing is a revolutionary curing process which has lot of advantages more than the conventional curing process. Internal Curing is a practical and applicable method that can supply extra water throughout the concrete mixture in order to complete the cement hydration process. This can be done by using lightweight aggregate which replaces some of normal and conventional aggregate in the concrete mixture. Water that absorbed inside expanded lightweight aggregate can provide ad-additional water throughout the concrete mixture for curing process. According to the international context, lot of international researches on performance evaluation of internally cured concrete has been conducting. And also this method is used internationally for various concrete applications. Internal curing process is widely used for concrete road construction because of its advantages. As a one of rapid developing country, in Sri Lanka yet there is no better technical knowledge and materials to implement this method for road construction process. And also There is no good research in order to find locally available materials and to evaluate performance of internally cured concrete for Sri Lankan road construction according to the Sri Lankan climate and readily available local resources. This research focused on the method of selecting suitable locally available resources in any country as internally curing concrete aggregate and to evaluate internally cured concrete relevant to the local context of that country. As well the main objective of this research is to select or produce a suitable internally curing concrete aggregate using readily available local resources in Sri Lanka and to find a suitable method to develop the marginally suitable aggregates. That includes the characterization of locally available lightweight aggregates to evaluate the performance of internally curing concrete.
item: Conference-Abstract
Minimize nearby structure damage issues in road construction
(Department of Civil Engineering, University of Moratuwa., 2016-08) Chandana, NHS; Mampearachchi, WK; Pasindu, HR
The purpose of this research is to minimize the nearby structure damage issues in road construction. Vibration caused various types of structural damages and it may finally affect the project progress. Although, there are systems to control these issues, it is reported that available systems are not reliable, effective and systematic. Even though, there are many research studies about quantitative vibration studies, nobody presented systematic holistic solution for these problems. Objective of this research is to minimize the nearby structure damage issues in road construction and improve sustainability of road construction projects. Firstly, existing vibration and structure damage monitoring systems of Sri Lanka and other countries were studied. Secondly data regarding existing system from experience site and Highway engineers were collected. Finally vibration when do major vibration generation road construction activities which used heavy vibrator rollers were monitored. Damages due to vibration depends on structure type, vibration value and affected time period. Those factors are taken into account to establish a systematic method. This method and guideline will provide fair solution to both parties who affected with vibration consequences and construction. For the survey, it is used hilly terrain area road section with similar subgrade condition. On the basis of the results of this research, it can be concluded that vibration limits are exceeded its damage limits in nearby structure and current boundary limits are not in optimum range and it should change with structure condition and baring capacity . According to questionnaire survey 84 % engineers think existing system should improve to meet sustainable road development and 85% engineers think vibration monitoring system is required for construction activities. This research generated three major outcomes which are very valuable to road construction sector. Those are vibration contour map for various type of compaction activities. Secondly, guideline for contractors and affected parties and data of deciding vibration affected boundary for specific road construction project.
item: Conference-Abstract
Developing prioritization indexes for provincial road networks using AHP
(Department of Civil Engineering, University of Moratuwa., 2016-08) Gunasoma, HDS; Pasindu, HR; Pasindu, HR
In pavement management, Prioritization involves ranking the pavement sections with respect to the identified set of factors by using subjective judgment or adopting quantitative methods. In view of the complexity involved in the decision making process, subjective evaluation based on expert‟s judgments is unavoidable. This study identifies priority factors that affect the pavement maintenance planning and it developed prioritization indexes for formulation of the maintenance strategy in the provincial road agencies. Priority factors were identified by the opinion survey and through a comprehensive literature survey. Sample consists of the Engineers of provincial road agencies and sample is selected as random sampling techniques. Based on the opinion survey and literature survey, five main priority factors were finalized namely pavement condition, traffic volume, connectivity to local road network, land use pattern and importance to community. Those factors were relevant to local context in ranking pavement sections for maintenance. In order to quantify the importance to community factor it was spitted into four sub factors namely, civic centers, cultural events, produces in area and alternative roads during maintenance. In this study Analytical Hierarchy Process (AHP) was used as the prioritization approach. AHP is one of the most important methods for prioritizing road maintenance factors since alternatives are very high in ranking process. AHP is used to make decisions in a more rational way and to make them more transparent and better understandable. It was found that a higher weight was given to importance to community factor followed by pavement condition, traffic volume, connectivity to road network and land use pattern. Under the importance to community, Civic centers have the highest priority. Cultural events also have the significance priority since the study was done for provincial road network.
item: Conference-Abstract
Development of a guideline for traffic signals at individual intersections
(Department of Civil Engineering, University of Moratuwa., 2016-08) Jayasooriya, NK; Bandara, JMSJ; Pasindu, HR
With the ever increasing traffic congestion, number of methodologies are developed to initiate sustainable traffic management solutions for the current traffic demand. Rather than going for mega scale infrastructure improvements which would be costly as well as time consuming in short term, it is needed to introduce short term traffic management initiatives to reduce traffic congestion. This has been identified as the research gap, where the main bottleneck of the system has been the delays at signalized intersections. This research identifies the issues with the current traffic signal system, and aims at developing a guideline for traffic signals at individual intersections. It has been identified that the behaviour pattern of the drivers can be categorised as aggressive and peaceful behaviours (Trabia, 1999). Gradinescu (2007) also refers to the parameters needed in identifying the aggressive driving behaviours, which were quite useful in directing the research in producing the methodology. With the aggressive driver behaviour patterns expected in Sri Lanka, the guideline to be developed has been categorised into four; guidelines for geometrical details, phasing arrangements, signal timing, and pedestrians. The data was collected for twelve intersections in Colombo area. Further, the collected data was analysed using VISSIM traffic simulation software, which is already calibrated for the Sri Lankan condition. Further, proper logical arguments are also developed in proving and verifying the guidelines. As for the geometrical details, when no separate right turn is available, it is recommended to use leading green for the right turns in signal design. If the intersection is supposed to have separate right turn lanes, it is recommended to use either lagging green or leading green for the right turns depending on the size of the right turn bay and vehicle volume. Further, with respect to left turns, it is recommended to provide a separate left turn, if the amount of left turns expected are more than the equivalent per lane amount of through movement. With respect to the selection of phasing arrangement, it is suggested to start off every intersection with two phases and use 1300 as the maximum number of right turns plus through volumes that can pass through an intersection during one hour green period. When any phase is violated, it is proposed to split the phase. If separate right turn lane is available, go for leading green for right turns only phase, even when both approaches have right turn lanes. If right turn percentage is significantly smaller, it can be accommodated at the end of Amber. Further, if no separate right turn is available, go for either complete through plus right turn phase for each direction or go for leading green for right turns only phase. As for the guidelines for traffic signal timings, the saturation flow for the Sri Lankan condition should be kept as 2000 vehicles per hour, which is verified through simulations. Further, maximum cycle time should be kept as 150 seconds for 4 phase intersections and 120 seconds for three phase intersections in order to reduce the overall delay for all the phases, except under very special circumstances. With respect to the guidelines for pedestrians, when heavy pedestrian movements are expected, it is proposed to delay the left turns by few seconds. It is also suggested not to provide the pedestrian phase with left turns if the speed of the turning vehicles is more than 15kmph. In conclusion, based on the number of surveys, arguments and simulations conducted the above guidelines are developed in order to reduce the ever increasing traffic congestion that is currently experiencing in Sri Lanka and further research need to be conducted in traffic signal coordination for intersection clusters.
item: Conference-Abstract
Motorcycle helmet usage in a town in Sri Lanka: an observational study
(Department of Civil Engineering, University of Moratuwa., 2016-08) Gunathilaka, OHDC; Amarasingha, N; Pasindu, HR
Most of the motorcycles fail to offer the necessary protection for the riders in the case of a crash resulting increased crash severity. Numerous reasons have been already identified for motorcycle crashes by previous researchers and several countermeasures have been proposed to provide protection for motorcycle riders. Among them, the correct safety helmet usage has been widely discussed. A safety helmet is capable to reduce the severity but not to prevent a crash. The objective of this study was to identify the helmet usage pattern in a Sri Lankan town. An observational survey on helmet wearing characteristic and riding behavior was conducted in five locations at Ambalangoda town, in March, 2016 by covering A-Class, B-Class, C-Class- and D-Class roadways. The data on number of occupants, helmet usage patterns of the riders, pillion riders, and other occupants were collected along with their age (whether adult or child), and gender on a structured data sheet. A multiple counter was used to effectively count the helmet usage patterns and videos which were recorded at the intersections during the peak hours. Peak hours in this town are from 06:00 to 08:00; from 11:45 to 13:45, and from 16:30 to 18:30. Within peak hours data were collected in each location and spent five days for surveys to cover all five locations. The data on gender, age, helmet usage, roadway classes, and number of passengers were cross tabulated and percentages were calculated. The observation surveys indicated that overall helmet usage was as high as 90.5%. However, out of the 7,332 users, only 2,298 (31.3%) users properly worn helmets. It is noted that the helmet usage rate was low among children, which is of particular concern. These results can be used to identify the measures to increase the helmet usage rate in Sri Lanka and some ideas were presented.
item: Conference-Abstract
Traffic impacts at Dehiwala flyover on level of service of the intersection: case study
(Department of Civil Engineering, University of Moratuwa., 2016-08) Paulusz, NN; Sirisoma, RMNT; Pasindu, HR
Delay is the principal measure of level of transportation service at a signalized intersection. It was discovered that Dehiwala intersection has being over burdened with newly constructed flyover resulting in traffic delay problems. In addition to designing appropriate access for new developments, it is vital to maintain a satisfactory level of service. Therefore, this traffic impact study will be helpful to determine the need for any improvement. Data were collected through direct field surveys (delay survey, speed survey, classified traffic counts, Queue length survey, Pedestrian counts and Bus circulation survey) under mixed traffic operations and poor lane discipline prevailing at Dehiwala intersection. It was found that traffic congestion occurs at the intersection from 8.00 a.m. to 9.00 a.m. During this period the overall efficiency of the intersection is unacceptable. Queue formation of buses at the far side bus stop towards Colombo reaches 20 buses during the peak blocking the entire intersection. The adverse impacts which causes delay are long queues which form along Galle main road (A2) in both directions thereby vehicles entering the intersection from Galle side and Colombo side waste time in queues. Reduction in approach speeds at all four approaches were observed during the study period. After collecting data on queue formation, waiting time for buses, traffic flow, delay for vehicles and average speed, it was observed that there is no advantage of installation of flyover at the location. Observed average speed on Galle Road during the peak period is around 8 km/h having the flyover with two lanes in the same direction. Compared to the delay of vehicles, calculated Level of Services of Four approaches Hills Street, Galle Road towards Galle, Station Road are in under category „D‟ and the Galle Road towards Colombo is under category of „E‟. Considering factors which contribute to above impacts, measures such as relocation of far side bus stops, area traffic management plan, expedite the extension of Marine Drive up to Dehiwela are recommended to overcome traffic congestion and allow the intersection to maintain a satisfactory level of service.
item: Conference-Abstract
Delay analysis at a signalized T intersection using VISSIM software
(Department of Civil Engineering, University of Moratuwa., 2016-08) Vajeeran, A; De Silva, GLDI; Pasindu, HR
Traffic signal delay is one of the major problem people face in urban areas. Though the traffic signals sometimes create a delay itself, they are needed for the safety of the junction to prevent collision between several vehicle movements. Delay is a component related with time which is more precious. A proper traffic signal arrangement has to be implemented which can optimize the delay for all vehicle moments through the junction. Apart from signal timing arrangement, other factors such as geometry also influence the delay at an intersection, which should be considered when analyzing the delay. The aim of the research is to analyze and find the parameters influencing the delay at a signalized intersection and get an optimize condition which can reduce the delay. Katubedda Junctions which is a T intersection has been selected for the case study. The traffic simulation software VISSIM has been used for the analysis. The geometrical arrangement, signal timing and traffic flow data was collected through a video survey. Driving behavior parameters is the key to calibrate the software model to Sri Lankan conditions. This was achieved by changing the driving behavior parameters of the model and matching the propagated queue length in model with actual queue length. Some geometrical and signal timing changes were categorized into three different alternatives which were modeled in VISSIM with the existing condition as the base case. The results show that changes in signal timing arrangement and changes in the geometrical arrangement has to be done to reduce the delay at the selected location
item: Conference-Abstract
In depth analysis of Southern Expressway accidents
(Department of Civil Engineering, University of Moratuwa., 2016-08) Dharmasiri, HIMJTU; Mampearachchi, WK; Pasindu, HR
Southern Expressway is the first access control expressway in Sri Lanka. Currently it traverse from Kottawa to Matara and it was initially opened to public on 27th November 2011 from Kottawa to Pinnaduwa. Road accidents have become a normal and re-occurring phenomenon from the beginning of expressway operation up to date. Accidents bring a great loss of economy and property, and even the human life. This study focuses on analyzing data collected by Expressway Operation Maintenance and Management Division and Expressway Police Division based on expressway accidents from beginning of operation up to end of April 2016 . The objective of this study is to present accident trend between interchanges and comparison of accidents with other expressways based on accidents rate (Accidents per Vehicle Kilometer Travel). SPSS frequency analysis is based on the day, time, location, severity, causes of the accidents and conditions of locations. Accidents prone locations are identified by prepared accident map. Causes for the accidents are analyzed based on the three main factors as human, vehicle & infrastructure/environment. The causes of accidents and their general preventive measures are discussed based on safety audit process through the expressway. This report provides an in-depth analysis of accidents in selected period based on the various factors influencing accidents. Cumulative total of 2270 accidents with 14 fatal accidents have now been reported on the carriageway of Southern Expressway and 10.6% was Injury and 88.8% was property damage only. This is not a good trend for the expressway present as well as future. Most of the accidents have been occurred during the clear weather condition and 36.1% occurred during the rainy weather. 40% of accidents were reported in wet road surface condition. About 16 numbers of accident prone areas have been identified in between Kottawa to Pinnaduwa section. Human factors such as driver behavior, fatigue, negligence etc. are the main cause involving with the large number of accidents. This study helps for the improvement of safety through the Expressway network as well as planning of safety procedures during the future Expressway development. New improvement can be implemented to minimize the accident rate as well as severity.
item: Conference-Abstract
Develop a sustainable model for implementing driver improvement points (DIPs) in Sri Lanka
(Department of Civil Engineering, University of Moratuwa., 2016-08) Bandara, ALKMMP; Bandara, JMSJ; Pasindu, HR
This research mainly focuses to come up with a suitable Sri Lankan model which will support the sustainable implementation of “Driver Improvement points system” (DIPs) - as per the regulations published under the Motor Traffic Act from the extra ordinary gazette numbered 1726/12 and dated 05.10.2011. It has declared 22 offences that could be counted for DIPs. The design of DIPs was done with the main objective of identifying high risk motorists and habitual offenders and to suspend them from driving for a specified period of time. While correcting the attitude and improving the discipline of drivers in order to ensure that they will be more responsible and courteous on the roads and reducing the high number of road accidents which has brought great loss to the country over the years are the two main objectives of a DIPs system. DIPs are a mechanism already adopted in limited number of countries, mainly by the developed countries like USA, Canada and Australia, and as well as by some developing countries like Malaysia, Singapore and South Africa. The implementation of DIPs within Sri Lanka is still doubtful though the legal enforcement is already available, due to some practical issues. A fully integrated and well equipped monitoring system will be required in order to ensure the effectiveness and the transparency of the system. The infrastructure facility requirement of the system is very high and eventually it requires a fairly large initial capital investment which is very hard to bear by a country like Sri Lanka. On the other hand the high possibility of corruptions in the current Sri Lankan system is one of the major issues to be addressed in the implementation process as it will drastically affect the credibility of the system. In developing a sustainable model a comprehensive literature review was carried out on the DIPs systems implemented worldwide including the factors affecting the driver behavior. Further an opinion survey was carried out to get the public opinion and ideas of the proposed system. The sample group comprising of Private Vehicle Users, Professional Drivers and Passengers/Road users were addressed through two different ways in form of Google forms and the printed version of the same. The online questionnaire using Google forms mainly targeted the private vehicle users. The printed version of the same questionnaire was used to get the opinion of the people who do driving as a profession and the other road users. The results clearly show ensuring the effectiveness and transparency is a must for a credible system. Provision of valid evidence of the offence before marking any points is expected by almost all the parties involved. The new model proposed, points out the draw backs of the previous system and focuses on low cost methods such as body worn cameras, in capturing reasonable evidence of the offence.
item: Conference-Abstract
Systematic ratings of accident prone T – intersections on national highways
(Department of Civil Engineering, University of Moratuwa., 2016-08) Arulrasa, A; Mampearachchi, WK; Pasindu, HR
Road Traffic accidents and the resulting deaths have now emerged as one of the major safety and public problems. In this study, intersection geometry of roads were considered to rate accident prone T – Intersection locations in national highways. The only source of accident data in Srilanka is available with the traffic police. Availability of accident data is vital for identifying accident prone locations in the traditional data analysis process. However, insufficient data for statistical analysis and changes to the geometry of the intersection with improvement is a major drawback of analyzing the available data. In this study, a method is introduced to find and rate the accident prone T – Intersections with respect to road geometry without depending on traffic police accident data. The parameters of road geometry such as road width, vertical profile and type of movement and combination of these: - are considered as main influence elements and identified vulnerable factors of the each element. The lane width was classified as single lane, two lane and multi lane and approach road profile was divided into flat, medium and adverse. The turning movement types were classified into four types: M1, M2.M3 & M4 based on centre median configuration for traffic movement at the junction. Then the relative contribution of the elements to the accident prone T – Intersections was determined by using Analytical Hierarchy Process (AHP) with a rating system. The rating of each element was suggested by experts of Roads and Traffic Engineering. Expert ratings were subjected to consistency testing and AHP determines the weightage of each elements. It was found that road width is the most critical element of the road geometry and followed by vertical profile and turning movement type. The intersections did not comply with the model were further studied and identified the causes for lower or higher number of accidents in those locations. Most vulnerable accident prone T-intersections had the combination of, flat gradient of approach road, single lane width and open centre median in the major road of the intersection.
item: Conference-Abstract
Investigation of accidents in Colombo Katunayake Expressway
(Department of Civil Engineering, University of Moratuwa., 2016-08) Bandara, WRGM; Pasindu, HR; Pasindu, HR
Expressways are developed to provide high mobility and safety link between major cities in a country. Colombo Katunayake Expressway is 26 km expressway connected from Colombo to Katunayake where the major airport located. The objective of this research to is identifying the major factors for accidents related to road characteristics, user (driver and vehicle), and environment. 100m sections of the expressway for each direction are considered in for the accident data collection. Accident data includes severity including economical loss, weather condition, light condition and road surface condition which were recorded for one and half year period and created the data base. It is identified that majority of accidents 66.4% of total accidents cause due to road user (driver) behavior and vehicle related problems. Severity of accident has increased when there is a combination of above factors (road, user and environment). This would be suggested that the average accident rate is 1.3 per million vehicle kilometer. Only one fatal accident has recorded during the period which is was a motor bike entry and crash with a car and only 4.2% accident has caused serious injuries to road users. Since this is a partially opened expressway there is an issue relates to vehicle road worthiness, during wet weather conditions speed reduction are also identified as one of the major factors related to road user behavior. Therefore we can expect significantly reduce reduction of the accident rate through improving road user awareness and education on safe practices can be expected. Expressways are designed to improve the safety level of road user. Ttherefore it is important to identify the any issues that reduce the safety on expressways to ensure that the high safety standards can be achieved. The significant issue related to road characteristics is a surface water accumulation on the expressway at reverse curves due to the problem of changes of super elevation and cross fall. Therefore need to add the improved design improvement such as groves or use of porous pavement to improve drainage on such sections or by installing variable speed sign on such sections to notify drivers.
item: Conference-Abstract
Formulation of a rapid transit route network for Colombo
(Department of Civil Engineering, University of Moratuwa., 2016-08) Devasurendra, KW; De Silva, GLDI; Sirisoma, RMNT; Bandara, JMSJ; Pasindu, HR
Colombo, as many major cities in the world with a growing population and an expanding economy, is facing the challenge of meeting the demands of increasing mobility needs within the city in terms of quantity and quality. Over the past few decades, land transport in Colombo has evolved in to traffic clogged roads especially during the peak hours making access and mobility between households, work places and other important locations a time consuming and a tiring task. Therefore, improving the mobility and accessibility in the inner core of the city, has become one of the major requirement of the country. A review of literature for the possible interventions suggested that an elevated mode of rapid transit is the best due to the unavailability and high costs of lands in this area. The other supporting reasons for such a system are the comfort, ease of access, less obstruction for the existing road traffic and hence low travel time between origins and destinations. Therefore an elevated system is likely to attract more private vehicle users, provide more options for public transport commuters and reduce road traffic congestion while improving the accessibility and mobility. Formulating the most effective and efficient route network to solve the mobility issue is therefore at utmost importance. The access locations of the rapid transit system which is the most important component of the network, were identified with due regards to the major trip generation points (Residential areas, apartment buildings and etc.) and major trip attraction points (office complexes, schools, recreational facilities, transport nodes, super markets and public places like hospitals and etc.). Possible major stations (nodes) were selected within the walking distance (500m) of majority of these trip attraction and generation points considering the land availability and security reasons as well. The routes were identified through minimum spanning tree process in order to minimize the cost of construction by minimizing the total length required to cover the identified locations and by taking the difficulty of construction (sharp bends and etc.) and required land acquisition in to account. Possible connections between the nodes along the existing roads that are possible to connect were identified with their distances. All these links were converted to equivalent cost figures which has taken the length, difficulty of construction and required land acquisitions in to account. A cost matrix was then formed between the nodes. In order for the cost to be a minimum, these nodes have to be connected with the links with minimum possible costs. Therefore, the minimum spanning tree method was utilized to connect the nodes. Using the cost matrix, a minimum spanning tree was developed to connect the identified nodes (possible RTS stations). From the developed minimum spanning tree network, the RTS network was derived while giving due attention to the construction and operational aspects. Special attention was given to the possibility of creating loops and connecting links with other available transport modes such as railway and bus transport.
item: Conference-Abstract
Suitability of light rail transit (LRT) and monorail for Western Province, Sri Lanka
(Department of Civil Engineering, University of Moratuwa., 2016-08) Abewickrema, AWN; De Silva, GLDI; Pasindu, HR
Within Colombo CBD area, the existing passenger demand in almost all the roads and in the existing public bus transport service has been surpassed. Therefore, the traffic congestion is at its peak, where average travel speeds have come down to around 10-15 km/h in city roads. The necessity of sphere heading a long term solution is at an alarming stage. A new Rapid Transit System will be introduced in the CBD of Western Region. It will introduce new transit modes and will provide easy access to the major attractions in the system. It will ensure a higher quality service for everyone in terms of cost, time and safety introducing a new mode will help the rider to choose most appropriate mode of transport based on his trip purpose and hence will increase the modal shift towards the public transportation reducing the traffic congestion significantly. All the major points in the CBD will be connected by the new system. Faced with the escalating demand for public transportation in Colombo Metropolitan Area, transportation authorities are challenged to select a technology that will satisfy the often conflicting demands of high capacity and reliable service, urban fit, minimized environmental impact and budget restrictions. Main cause for the selection of LRT (Light Rail Transit) preferably referred as “Light Metro” over monorail and was its popularity corresponding to its versatility. Light Rail can run on all possible types of alignment (elevated, at-grade, tunneled), depending on the particular situation in a given area of a given city, such as: cost, density, station spacing, ridership, etc. Moreover, the same line can be running on one type of alignment in one area of the city and on another type of alignment in another area of the same city depending on the possibility. Since the proposed Rapid Transit system spreads through suburbs such as Battaramulla, Kottawa, Malabe, Kaduwela and Kadawatha, considerable portion can be accommodated at-ground level while blended facilities such as deports and stations can be located at ground level irrespective to line been at-grade or elevated will significantly truncate associated cost. It incurs lower operations costs as unlike for instance LRT does not pose switching issues. Although monorail is unable to expand as a network with crossings LRT could be expanded. Plus there are more providers across the world so - have the system at a very competitive rate with the best technology. The modern LRT system technology permits slender contemporary structural supports ensuring the aesthetic beauty of the urban context. LRT technology proliferated everywhere in the world beginning in the late nineteenth century to the present day, while monorail systems remain few and far between, says a great deal about the relative versatility, suitability, reliability, and cost-effectiveness. The number of cities in the world where monorails actually perform a general, practical urban transit function can probably be counted on the fingers of one hand and even there, –it is usually a single-purpose- and point-to-point operation. The key to more public transit, a better urban quality of life and less environmental damage from roads is to get something built and running ASAP. In the vast majority of cases, definitely will be Light Rail, because –that is what fits best in lower-density, automobile-oriented cities relative to all the identified demands a new "fixed guideway" system must meet.
item: Conference-Abstract
A sustainable financing mechanism for urban rail projects: case study in Colombo, Sri Lanka
(Department of Civil Engineering, University of Moratuwa., 2016-08) Somawardhana, SA; Devasurendra, KW; Pasindu, HR
The existing transportation infrastructure in Sri Lanka is heavily auto-centric. However, given the high rate of depletion of global fossil fuel resources, as well as the limited land area available for expansion of roads in Sri Lanka, continued auto dependency is no longer viable as a basis for the country‟s long-term transportation strategy. Therefore, the Western Region Megapolis Planning Project plans to introduce a Light Rail Transit (LRT) System in Colombo and its suburbs, in order to reduce dependency on fossil fuels and combat the issue of traffic congestion. An effective financing mechanism is one of the key factors crucial to the success of a railway infrastructure project. Hence, this study sought to propose a viable financing mechanism for the proposed Light Rail System in Sri Lanka, by assessing methods of financing for railway infrastructure utilized in other countries, including the UK, the USA, France, HongKong, India, and Singapore. The methods studied include tax increment financing, the rail-property development model, hypothecated taxes-and congestion pricing, as well as various combinations of these methods. Ten case studies were selected from various countries. These case studies were assessed on the following factors, in terms of their similarity to the existing situation in Sri Lanka; volatility of the project environment, strength of political support for the project, existing legal framework for taxation and land acquisition, and level of integration between government planning bodies. Next, the projects were assessed based on the funding mechanism utilized in the project, against the following aspects; allocation of risk, effectiveness of project planning-and organizing for operations. The findings indicate that a combination of hypocenated taxes and the rail-property development model could be adapted in the Sri Lankan context to ensure the continued viability of the proposed LRT system.
item: Conference-Abstract
Micro simulation for airport curbside and roadside operations BIA
(Department of Civil Engineering, University of Moratuwa., 2016-08) Udayanga, PAS; Pasindu, HR; Pasindu, HR
This focuses on analysis of existing level of service (LOS) of the airport curb side and roadway operations at the Bandaranaike International Airport (BIA) and how micro simulation can be used as a tool for LOS improvements. Considerable amount of research has been devoted to modelling airport terminal operations and performance evaluation. Curb side performance has been proved to be a significant component in the overall LOS of an airport. Curb side and roadway operations were further categorized in to micro level components of (1) departure and arrival porch queue; (2) departure and arrival roadways; (3) access roadway; (4) weaving segment; (5) circulation roadway. Sensitivity of the variables was considered to identify the critical parameters. Simulation of the each component in single model enabled to analyse the impact on overall performance by the each component. The operating characteristics of airport terminal curb side differ significantly from those of most other roadways due to several reasons such as vehicle dwell time and driver behaviour etc. Six different vehicular movements can be indentified at the weaving segment and traffic flow of departure and arrival roadways continuously disturbed by the pedestrian crossings in peak hours. Simulation of aforementioned locations provided useful information for analysis with future demand. Analysis of vehicular traffic, travel mode choice, curb side roadway vehicle queues, vehicle dwelling times and passenger occupancy level will provide useful information for developing plans for operational improvements as well as for planning future expansions. Using the available data, and the data provided by the model, demand and the capacity of these facilities were evaluated to estimate the existing LOS. Multivariate regression is used to obtain mathematical relationships of user characteristics which correspond to the dwell time. The analysis was done adopting an analytical approach instead of the traditional simplified method given in International Air Transport Association (IATA) manual as a design guideline. Measures were identified to improve the operational efficiency of these facilities and proposed improvements are proposed to ensure good operational efficiency for the forecast future demand. QAT-ACR (Quick Analysis Tool for Airport Curb side and Roadways) can be used to validate the model using available data.
item: Conference-Abstract
Waterway transportation – an alternative mode for reducing the urban traffic congestion (a case study of Colombo City area)
(Department of Civil Engineering, University of Moratuwa., 2016-08) Senavirathne, SWMP; De Silva, PCP; Bandara, JMSJ; Pasindu, HR
The waterway transportation specifically as an inland transportation system has been providing many solutions for improving the functioning of urban logistics. (Taniguchi, Nemoto 2008) The following study was carried out to identify the feasibility of establishing a waterway passenger transportation system based on the Beira Lake and the canal system in the Colombo Municipal Council area (CMC). The CMC and the Western Province undergoes a huge development project which is Western Region Megapolis Master Plan which expects an increment up to 4.4 million passenger trips by 2035 which is 1.9 million in the present situation. (WRMMP, 2016) These rates would certainly increase the traffic congestion in the CMC area and would cause for more economical loss which is 32 billion rupees annually in the present due to the increased traffic congestion. The study focuses on establishing an alternative transportation system to avoid the traffic congestion in the CMC area. Initially, using the GIS Thiessen polygon tool the study area was sub divided into zones based on the nodes of the road network. A Trip Generation – Attraction model was used to calculate the number of trips transferred through the zones based on the respective population and employments. Using the Gravity Model the number of trips were distributed among the zones considering the centroid as the trip origin and destine point. Secondly, it was identified that the trips included in the roads where the carrying capacity has been exceeded can be transferred through the waterway transportation system. The study findings can be concluded that the Beira Lake and surrounding of 1 km buffer zone generates approximately 4 million trips of the length of 3.5 km which can be considered as prospective trips for the waterway transportation system. The study showed that the waterway transportation system is a well adoptable alternative mode to ease the traffic congestion in the CMC area.

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