Transport Research Forum

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item: Conference-Abstract
Characteristics of school trips in Colombo
(Department of Civil Engineering, University of Moratuwa, 2019-09) Mishael, MJ; Amarasingha, N; Pasindu, HR
This study explores the characteristics of travel mode choice of school trips made by students whose age between 11 to 18 years. The objectives of this study were to investigate the factors affecting travel mode choice of school trips and to recommend mitigation strategies to reduce traffic congestion due to school trips in Colombo. Questionnaire surveys were conducted among school students in Colombo to gather information related to the mode of transport to and from schools. The factors that explain the reasons for the choice in the particular mode of transport were investigated. A model is developed to understand the relationship between each of the determinants and the choice of mode transport to analyze how this study can be utilized to benefit the overall modes of transport available for school children. The pilot study was conducted among randomly selected 65 students from the Colombo district. The study went on to identify the mode of transport commonly used by students. It was identified that 53% of students used private mode of transport whereas just 34% of students used public transport when traveling to school. Moreover another 11% of the respondents went to school by walking. As per this study, it was identified that nearly 42% of the students were accompanied by parents or guardians when traveling to their respective schools. However, a similar 45% of the students who were taken into a pilot study, traveled to school alone. When considering the average distance to school from home, 79% of students traveled less than 10 km to school. Hence, this study clearly identified that the use of private transport methods has been a major factor contributing to the traffic congestions in the area, hence, improved public service transport, improved cycle paths and set-up of appropriate pedestrian paths are identified as major factors that can resolve this pertaining issue.
item: Conference-Abstract
Estimation of vehicle kilometers travelled in Southern Province, Sri Lanka
(Department of Civil Engineering, University of Moratuwa., 2016-08) Weerasekera, TD; Amarasingha, N; Pasindu, HR
Estimation of vehicle kilometers travelled (VKT) is used in traffic and transport planning for various purposes such as allocating resources, estimating vehicle emissions, computing energy consumption, analyzing crashes, assessing traffic impact, and making road safety policy. Therefore, it is crucial to have an accurate timely estimation of VKT. Both traffic and non–traffic measurement methods are popular among the transport planners and researchers. Very few studies have conducted in Sri Lanka for estimating the VKT, but timely data on VMT could not be found. This study proposes to estimate the VKT based on the number of household daily trips, which are collected through the interviews. All trips made by household members are surveyed for a single “travel day,” with interviews conducted so that every day of the week, including holidays. The interviewer records the mode of travel, total number of kilometer travelled, and number of passengers. The modes considered in this study are car, van, motorbike, bicycle, three-wheeler, and jeep. The socio-demographic information is also collected and this includes age, gender, employment status, and income. The estimation of total VKT is derived from survey respondents‟ total number of kilometers each travelled during the previous 12 months in Southern Province, Sri Lanka. Variations in VKT among males and females, different age groups and income groups are identified. When investigating VKT by gender, it is observed yearly VKT of males were higher than females. People in age group of 30-34 years has more yearly VKT than any other age groups. By investigating the residence areas, it is not observed much differences on VKT between rural areas and urban areas. The collected data are also used to estimate the personal kilometer travelled and characteristics of travelers in Southern Province. The timely estimation of VKT in Sri Lanka is mainly important for road safety analysis, economic analysis, resource allocation, and urban planning. This method can be considered by policy makers to estimate the VMT in each year in all provinces for different vehicle types.
item: Conference-Abstract
Evaluation of roadway-railway level crossings in main line from Colombo to Polgahawela
(Department of Civil Engineering, University of Moratuwa., 2018-08) Ragulan, K; Amarasingha, N; Pasindu, HR
When a railway line crosses a road or a path at the same level, it is called a Level Crossing (LC). The total length of the railway lines in Sri Lanka is approximately 1930 km (SLR, 2011). 1047 crossings have been reported. Out of these, 128 crossings are protected by electrical barriers and 139 are protected by mechanized barriers. A great amount (758) is manned by barriers while an amount as low as 17 are manned by farm type gates. About 151 gates have a bell and flash light system. There are about 457 unprotected gates in the country, accounting for 37%. The main objective of this study is to evaluate the railway-roadway LC safety, because a significant number of rail crashes are being reported in Sri Lanka at LC. Four years of railway crash data, LC characteristics, rail line characteristics, and highway characteristics, were collected at the main rail line from Colombo to Polgahawela. Special attention was paid to different types of LCs, focusing on their methods and their functional capacity. Furthermore, the shortcomings found in the system were analysed using data pertaining to the 62 LCs found between Colombo to Polgahawela. The details regarding these LCs, their nature, construction, location, and intermittent distances were obtained directly from the Railway department. Then linear regression models were used to identify whether these predictor variables, which successfully predict an outcome, crashes. The locations which had appalling shortcomings such as the unavailability of barriers found in the LC, the prolonging of the bell sound for a considerable time, the elderly being employed in unprotected LCs without their basic facilities or wages being ensured, LCs and roadways running parallel and road traffic getting entangled in the LC, and the view of approaching trains getting blocked by towering buildings and trees, were successfully identified. Based on the data collected, the locations that needed immediate attention were pointed out. Statistical analysis further showed that the distance to the nearest curvature from the direction of Colombo and Polgahawela, the sight distance from the upside and the bottom, availability of a passive protection system, have a significant influence on the occurrence of crashes. The main intention of this research is to minimize the number of accidents that occur at the crossing of main line. The sample taken for the study is convenient, due to the fact that the population can be accessed appropriately. The results can be considered as general, though there might be slight variations that could arise, as some of the LCs, especially in the rural areas of the country, have less trains and vehicles on roads. Furthermore, some solutions and recommendations have been put forward, taking into consideration the modern methods utilized in this field.
item: Conference-Abstract
Experience in calibrating the VISSIM microscopic simulation model for a signalized intersection
(Department of Civil Engineering, University of Moratuwa, 2020-12) Gunathne, D; Amarasingha, N; Wickramasighe, V; Kulathunga, A.; Perera, HLK
Traffic microsimulation software is a traffic management tool which is currently being used in various countries to provide traffic management solutions. For developing countries like Sri Lanka, it is possible to observe a mixed heterogeneous traffic condition which includes lack of lane discipline, lack of lane marking, etc. The calibration process should be done before using the microsimulation software for local conditions in those countries to make the model results reliable and accurate and after the validation process, it is possible in simulating traffic management solutions. The main objective of this research study is to calibrate the VISSIM software for heterogeneous local traffic condition as the software is originally developed for homogeneous traffic conditions. VISSIM models which were calibrated previously for Sri Lankan traffic conditions are available and initially, the validity of some those models was tested. However, the simulated results of those models did not give the actual traffic characteristics in the study area. Also, in the VISSIM models calibrated previously in Sri Lanka, the driver behaviour parameter values were randomly selected and tested them on the VISSIM, but in this study, the calibration of driver behaviour parameters was done minimizing the simulation error percentage using a Genetic Algorithm (GA). The GA was used rather than randomly selecting the parameter values as it will provide with higher accuracy of the optimum values of the driver behaviour parameters and also it is fast compared to selecting the parameters randomly. The calibration was done in a signalized intersection focusing the driver behaviour parameters. Ten most sensitive driver behaviour parameters were identified through literature survey which is looking ahead distance, look back distance, average standstill distance, additive part of safety distance, multiplicative part of safety distance, distance driving, distance standing, minimum headway, waiting time before diffusion and safety distance reduction factor. The model was done for the Malabe three-legged signalized intersection and the average queue length was considered as the Measure of Effectiveness (MOE). Queue lengths were measured by using 5m marking tapes which were placed at 5m intervals in all the legs of the intersection. The data were input to the VISSIM software including the road geometry, and the signal timings related variables which measured at the intersection. The traffic volume and vehicle composition at each leg was recorded using video cameras and the videos were analyzed manually to gather the required data. The intersection was modelled in VISSIM software and the mean absolute percentage error (MAPE) for the intersection was calculated by using the observed average queue length and the simulated queue length. For that GA optimization was done using the MATLAB GA Toolbox for the fitness function developed based on the percentage error, between the observed and simulated average queue length, under different driver behaviour parameters. The maximum value for MAPE was considered as 15% as recommended by literature. In future, the calibrated parameter set will be validated with similar intersections and it will be used for simulations of traffic in the area.
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
An observation study on un-signalized marked midblock crossings in Colombo suburban
(Department of Civil Engineering, University of Moratuwa, 2018) Thevarajan, J; Amarasingha, N; Pasindu, HR
A pedestrian crossing is a place designated for pedestrians to cross a road where they can cross safely across the flow of vehicular traffic. It also makes the pedestrians easy to be spotted by motorists, by keeping them together, and Mid-block pedestrian crossings are marked crosswalks placed between intersections. Before crossing, pedestrians check the traffic in right side, left side, then again, the right side. Drivers must slow down and stop when a pedestrian steps onto a marked crossing, giving way to him/her. Crossings with poor visibility have zigzag white lines marked in the middle of the road to warn drivers. The aim of this study is to investigate the pedestrian road crossing behaviour at uncontrolled midblock locations in Sri Lanka which operate under a mixed traffic condition. It was identified that all the unsignalized midblock crossings from Malabe to Kaduwela in B263 roadway of Sri Lanka operate under a mixed different traffic flow. The data on the gender and approximate age of the pedestrian, crossing pattern, mobile phone usage of pedestrians while crossing, the fact whether a weight is carried or not, and the crossing’s geometry, were collected. All these data were collected from Malabe end towards Kaduwela end, using a video survey method, covering all the pedestrian crossings. Each and every video footage was recorded during 8:00 am to 9:00 am in weekdays during the months of July and August, 2017. Each and every characteristic of crossing and pedestrians were compared using the statistical inference theory. The overall average waiting time at the road segment considered was 6.54 seconds. When investing the waiting time by age category, it was observed that waiting time of children is lower than other categories. Elders opposing to children had more waiting time than others. This showed that middle aged people were paying more attention when crossing the road than children or elderly people. Therefore, children need to be given more attention. Most people were willing to cross the road as groups. It may be due to safety reasons. When considering the crossing speed, results showed that crossing speed of children was higher than that of adults. Statistically significant speed differences between males and females were also observed. When a person individually crossed the road, the crossing speed was higher than when crossing as a pair or a group. Straight crosswalks are designed to minimize the pedestrians’ crossing distance and pedestrians are expected to walk straight. However, about 48% of pedestrians did not walk straight on the crossing. This study revealed pedestrian characteristics and differences between pedestrian groups at the uncontrolled midblock locations in Colombo suburban. The results of this study can be used for traffic safety improvement programs. For an example, advanced warning messages and higher slight distance could be suggested in the crosswalks where more children are expected, as children did not pay much attention in crossings. Awareness and education programs could be prepared, encouraging pedestrians to walk straight when crossing as 48% did not walk straight.
item: Conference-Abstract
Traffic conflict analysis for pedestrian crossings at un-signalized pedestrian crossings in Kandy
(Department of Civil Engineering, University of Moratuwa., 2019-09) Abeyrathne, MCC; Amarasingha, N; Pasindu, HR
Road traffic safety is normally measured in number of crashes and the consequences of the crashes in terms of severity. When the crash data are not available, the Traffic Conflict Technique (TCT) is used as an indirect method for determine the magnitude of the safety problem. TCT provides information on relative risks to diagnose the types of problems at a particular location, and it represents efficient tool to check location safety issues when there is limited or no crash data. The Lane Based Post Encroachment Time (LPET) will be the conflict analyzing method which used by many researches including Almodfer et al. (2016) followed to identify the pedestrian traffic safety in this study. LPET is the time difference between when the pedestrian leaves the conflict zone and at the same starting time when the vehicle approaches the conflict zone related to each lane. Pedestrian crossing area will be selected as the conflict zone in this method. For each pedestrian who uses the conflict zone, the time of he/she leaves the conflict zone and the time of the vehicle arrives the conflict zone is recorded. This study was conducted at two marked un-signalized crossings in Kandy; Katugasthota -Kandy road and Peradeniya-Kandy road. The pedestrian crossings which were selected to conduct the research were on four-lane roadways having flexible pavements with good condition. Data were gathered monitoring the videos recorded during the peak hours at the pedestrian crossings. For each pedestrian crossing 100 pedestrians were observed covering the approaching from both side of the crossing. The pedestrian crossing in Katugasthota-Kandy road had 50.5% of slight conflicts, 24.5% of serious conflicts and 25% potential conflicts for one direction. The other direction had 50.5% slight conflicts 33% of serious conflicts and 16% of potential conflicts. The crossing at Peradeniya-Kandy road had 40% of slight conflicts, 34% of serious conflicts, and 26% of potential conflicts for one direction. The other direction had 36% of slight conflicts, 39% of serious conflicts, and 25% of potential conflicts. The percentage of serious conflicts in Katugasthota-Kandy road crossing was high that may be due to the placement of a Filling station in front of the pedestrian crossing. Also, the existence of a bus stop near the pedestrian crossing in Peradeniya-Kandy road may be the reason for high percentage of serious conflicts in that crossing.

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