Road crashes are a global concern, and they disproportionately affect younger drivers due to their inexperience and risk-taking behaviour. In Sri Lanka, the higher risk of traffic crashes among younger drivers underscores the need for researchers to study their driving confidence and behaviour. Such research could help mitigate the risks of future crashes. This research surveyed 400 young adults using a paper-based questionnaire to assess their confidence in various driving conditions: daytime, peak hours, nighttime, rainy weather, and hilly roads. It also examined risky behaviour such as smoking while driving, driving under the influence of alcohol, using a phone, and making illegal U-turns. The analysis employed Cronbach's Alpha reliability statistics, inter-item correlation, and Binary Logistic Regression (BLR) modelling. Participants' opinions on the Sri Lankan driving license process revealed that 16% rated it as good, 25% as average, and 59% as bad. Findings highlighted that increasing young drivers' confidence during nighttime and high-traffic congestion conditions reduces the likelihood of crashes. Confidence during nighttime and rainy conditions, along with perceptions of the licensing process, significantly influence crash involvement. Furthermore, risky manoeuvres, like overtaking in restricted areas, increase crash risk. The study highlights the importance of improving driver education and fostering safer behaviour to enhance road safety among young drivers in Sri Lanka.

The lack of up-to-date traffic volume data leads to multiple challenges in transportation planning. This study focused on developing an Average Daily Traffic (ADT) prediction model for road sections where timely ADT counts are unavailable. For the study, two major roads in a developing country were selected and segmented into uniform road sections in length. These two road segments traverse different administrative districts in the country that are different in land use, population density, economic activities, etc. For each section, ADT and socioeconomic and built environment-related factors were collected, and a multiple linear regression model was developed. Population density, number of intersections, and area type variables were statistically significant with a 95% level of confidence and with an R-squared value of 0.784, indicating a reasonable relationship. This alternative approach helps to estimate ADT on road sections where transport planners experience a lack of timely traffic volume data and to make accurate decisions.

Pedestrian Level of Service (PLOS) is a crucial measure of pedestrian experience at signalized intersections. Existing studies primarily focus on vehicular LOS, leaving a gap in pedestrian-specific research. This study aims to develop a PLOS model for heterogeneous traffic conditions. Data was collected through field observations and perception-based surveys at three major intersections in Colombo, Sri Lanka. A PLOS model was developed using significant variables: vehicular volume, pedestrian delay, and pedestrian crossing speed. The model's accuracy was validated against standard models and perception-based surveys. Threshold values for PLOS grades were determined using k-means clustering. The findings highlight the need for improvements in pedestrian facilities, such as accessible crossings and longer crossing times. These insights are valuable for policymakers and traffic engineers to enhance pedestrian safety and mobility.

This study examines the impact of road surface distress, such as cracks, potholes, and unevenness, on road capacity, highlighting its role in maintaining efficient and safe traffic flow. The research aims to analyze the relationship between road capacity and pavement distress to provide insights for improving traffic efficiency and safety. Data were collected during morning and evening peak periods in the western region of Sri Lanka, focusing on two road sections-one with visible distress and one without. Road capacity was estimated by analyzing traffic flow and vehicle density, while distress was quantified using International Roughness Index (IRI) values obtained through a smartphone-based application. Findings showed a significant reduction in road capacity in the distressed section, with an average loss of 13.54%. IRI values further supported this, with 1.9 m/km in the non-distressed section and 8.02 m/km in the distressed area, highlighting the critical need for road maintenance to ensure efficient traffic movement.

Travel mode choices for children under five years old have not been fully explored in past research studies The main objectives of this study were to identify travel characteristics of children aged below five years, travel mode choices for them, and investigate the factors affecting their selection. A survey using a questionnaire was conducted with parents in the Western Province of Sri Lanka to collect data. It revealed that private cars as the most frequent vehicle choice followed by public buses. The Multinomial Logistic Regression analysis identified the age of the child, distance, income, type of vehicle owned, and walking time to the nearest public transport station as the main factors that affect the travel mode choice of children under five years old. Also, the habit of securing the child and the child’s familiarity with the use of a car seat when traveling in a private car were identified as factors that affect travel safety. The recommendations were provided to policy makers, parents, and the public in order for children to make safer, comfortable, economical, and sustainable trips. KEYWORDS: Travel Mode Choice, Multinomial Logistic Regression Analysis, child travel safety, child travel behavior

Speed humps are an effective traffic calming measure to improve the safety of road users. On the other hand, speed humps have certain drawbacks, such as increasing emergency response time, causing damage to cars, and high noise levels due to excessive traffic. These impacts further vary with different hump profiles. Thus, the primary objective of this research is to investigate how the geometric profile of speed humps affects vehicle speed and noise level. The secondary objective is to find the Level of Service in the presence and absence of a speed hump by using VISSIM microsimulation. In this study, Lake Drive Road, Nawala, was selected with four different speed hump profiles. The Sound Meter smartphone application was used for noise monitoring. A drone camera footage was utilized to capture vehicle flows while speed trajectories of each vehicle were developed using tracking software. The developed speed profiles were used for the simulation purpose. Then, a Multiple Linear Regression (MLR) model was developed and validated to predict the hump height for the desired speed reduction and desired noise level for each selected four-vehicle category. Further, the average noise levels were found to be higher than the Central Environmental Authority's permissible noise level, and it increases with the height of the hump. It was also observed that as the height of the hump increases, vehicle speed decreases. The largest speed reduction, 42.13 %, was observed in passenger cars, while the lowest speed reduction, 23.5 %, was observed in motorcycles. Therefore, speed analysis findings reveal that passenger cars have a significant speed reduction when compared to other categories. However, the average speed reduction for all vehicles was identified as 33.85 %, and VISSIM simulations revealed that the average Level of Service (LOS) drops to LOS C from LOS A due to the presence of the speed hump. KEYWORDS: Level of Service, Speed hump profile, Speed hump, VISSIM

Abstract As the population grows, so does the need for travel. With rising demand, public transportation providers are finding it difficult to meet the demand. As a result, alternative transportation services such as office transport are becoming widespread in Sri Lanka. This study aims to determine the service quality of office transport services based on user perceptions and expectations of the service. Recently there is only one study carried out in Sri Lanka focusing on office transport services. A questionnaire survey was conducted to collect data on passenger perceptions and expectations. This questionnaire survey is done within Colombo District, Sri Lanka to assess the Office transport services. Respondents were asked to rate certain qualitative characteristics of the office transport service based on their perceptions and minimum expectations of the service. In this study, Factor analysis and Structural Equation Modeling (SEM) were used to analyse the data collected through questionnaire survey. It was identified that there are three primary factors affecting the service quality of office transport services which are vehicle, safety and timely performance. Using the final SEM model, it was identified that vehicle is the most affected factor for the service quality of the office transport services. Based on the findings of this study recommendations have been made to improve the service quality of the office transport services.

In developing countries with heterogeneous traffic, such as Sri Lanka, it is possible to observe severe traffic congestion at intersections and traffic corridors. The main objective of this study was to demonstrate the optimization of traffic signal controllers using VISSIM microsimulation software. It aimed to minimize traffic congestion, emissions, and fuel consumption. This study focused on developing a traffic signal controller optimization program for a congested traffic corridor which consisted of a three-legged signalized intersection, a four-legged unsignalized intersection, and a three-legged unsignalized intersection. The entire corridor was modeled here, and the already signalized three-legged intersection was optimized. Traffic signal controller optimization was done separately through the built-in optimization features in VISSIM and Webster’s Method. The results showed that emissions and fuel consumption were reduced by 14.89 % in VISSIM optimization and 14.11% in optimization using Webster’s Method. Through the comparison between the VISSIM optimized signal timing and manually calculated signal timing, it was found that the signal timing optimization provides much more improved results than the manual signal timing calculations. Using the proposed methodology, the traffic signal controllers can be optimized within a short duration in very few steps without any iterations compared to the existing traffic signal controller optimization techniques. Therefore, the proposed methodology is a good alternative method to optimize the traffic signal controllers.

Modeling effective vehicular traffic is a highly contested topic, especially in developing countries like Sri Lanka, which has a wide range of driving conditions. VISSIM microsimulation software is currently used by Road Development Authority (RDA) and relevant authorities to perform traffic management solutions in Sri Lanka. However, it is required to do modifications to the existing driver behavior parameter values to effectively reflect the realistic traffic conditions observed in the real-world in the simulated model. The main purpose of this study is to calibrate the VISSIM driver behavior parameter values using a genetic algorithm (GA). The methodology and results of the VISSIM model’s sensitivity analysis and calibration, which was developed for the Malabe three-legged signalized intersection, are presented in this study. A sensitivity analysis was used to find the most sensitive driver behavior parameters. Using the multi-objective GA optimization tool in the MATLAB software's optimization toolbox, the optimum driver behavior parameter values for these identified most sensitive driver behavior parameters were determined. The findings revealed that GA optimization is effective in reducing the difference between observed and simulated results.

Hundreds of pedestrians have died and many have been injured in the past decades as a result of Red Light Running (RLR) infractions. According to the United States Department of Transportation, 846 pedestrians have died and 143,000 have been injured in 2019 due to RLR violations. The majority of previous studies have focused on pedestrian behavior at an intersection, whereas only a few have looked into pedestrian RLR violations. The main objectives of this research are to find the pedestrians’ RLR rate in Sri Lanka and to find ways to reduce the RLR rate of pedestrians at the signalized crossing. Video observation surveys were conducted to collect data at three signalized intersections within Kandy city limits during weekdays for two hours per site. Pedestrian demographic variables such as gender and age; crossing characteristics such as crossing type, direction, crossing speed etc; and site characteristics such as crossing length, pedestrian green time, etc. were recorded. Chi-square and binary logistic regression tests were done. Results showed that out of 178 females, 130 had compliance with signal phases and out of 386 males, only 215 had compliance with RLR of a pedestrian. Furthermore, other independent variables such as age, crossing type, direction etc. were also associated with compliance RLR of pedestrians under Chi-square results. Based on the results of binary logistic regression, the variables such as gender, crossing type, number of traffic lanes, and pedestrian speed are significant when decreasing the log of probability -0.658, -3.040, -1.022 and -2.556 of compliance for RLR respectively. Variables that crosswalk utilization are also significant when increasing the log of probability of RLR 1.406 of compliance for RLR. The results would help develop safer pedestrian infrastructures and engineering countermeasures as well as assist the researchers and practitioners in better understanding pedestrian crossing behavior at signalized intersections. KEYWORDS:Pedestrian’s violation,Road safety, Signalized crosswalk, Red-light running.

The Cyclists and Motorcyclists detection in streaming traffic video has been a challenging task due to irregular movement within the road and smaller image size within the frame. This paper is proposed a novel method of image segmentation of cyclists and motor cyclists and subsequent detection with image moments in traffic video footage. However, isolation of pedal cycles and motorcycles with perfect object boundaries has been a challenging problem with respect to other vehicle categories in the context of image segmentation. Irregular shape image segmentation for pedal cyclists and motor cyclists using a novel recursive image segmentation algorithm is proposed in this work The recursive image segmentation algorithm is applied to extract image pixels of a moving object in the binary image. The extraction of all the pixels of a bicycle could be accomplished successfully using the proposed algorithm. Subsequently, pixel count, height, width and the image Hu moments are recorded and used to identify the motorcycle category. An accuracy of 91.2% was obtained for video footage duration of 6 minutes video sequence for the detection of cyclists and motor cyclists. This recursive image segmentation method has successfully been applied in identification of motorcycles in traffic video sequences.

Lane-changing algorithm developments through mathematical modelling and simulations have attracted attention over the past years. However, little has been done to investigate the interdependency between the dynamics of queues at isolated signalized intersections and the lane-changing behaviour of approaching vehicles at the intersection. This study aimed to identify the lane-changing patterns of vehicles upstream of an intersection in the presence of a vehicle queue in heterogeneous conditions. The study was conducted in a three-lane signalized intersection in Colombo, Sri Lanka with two dedicated lanes for right turning and a single lane for through and left movements. The data were collected on Monday and Saturday from 2.00 pm to 6.00 pm using a drone camera to encompass the peak and off-peak travel behaviour. The findings highlighted the most influential factors in the lane-changing occurrence in the perception of a queue. Therefore, the research findings are beneficial in identifying driver behaviour patterns in terms of lane changing influenced by a queue at signalized intersections.

Road safety assessment is imminent to reduce road accidents in Sri Lanka. The existing road safety assessments in other countries are inapplicable to Sri Lankan Road conditions as there are significant differences between the road conditions of Sri Lanka and other countries. This study aims to identify the governing roadside elements which are influential to the cause of accidents and can be used for road star rating. The study was conducted in three districts of Sri Lanka: Anuradhapura, Polonnaruwa and Kurunegala. The data for road characteristics were obtained through the Google Earth Web engine whereas accident data were collected from Sri Lanka Police. The variables such as road condition, road length, road width, delineation, shoulder condition, footpath, vehicle parking length, road divide status, roadside objects length, number of lanes, number of intersections, number of pedestrian crossings, and number of bus bays were analyzed to develop a Negative Binomial regression model considering the number of accidents as the dependent variable. The results reveal that six variables: number of lanes, road condition, number of intersections, road divide status, road section length and width of lane are significant towards the occurrence of accidents. Moreover, the results demonstrate the relationship between the road characteristics and the accident number which is crucial in road designing in order to reduce road accidents. The findings affirm the possibility in developing a road safety rating mechanism for Sri Lankan streets to standardize the road network with the international standards while enhancing the road conditions with reflecting to the required safety levels. KEYWORDS: Road safety, Road star rating, Sri Lankan roads, Negative binomial regression

Person Kilometers of Travel (PKT) provides all trip information of an individual including trips by motorized, non-motorized, public or informal public transport modes. Estimating PKT in developing countries seems much important as PKT is one of key parameters in transport planning and policy making. Since PKT focuses on an individual, it is influenced by socio demography of the person. However, timely PKT is not estimated by relevant agencies of Sri Lanka. The study focused on estimating PKT in Sri Lanka with travel mode distributions. A paper-based travel survey was conducted over all administrative districts in Sri Lanka for collecting trip information and socio demographic factors of people. 9,012 people participated in surveys resulting a 77.62% response rate. Respondents were asked to provide information of their trips in a typical week, in special holidays and seasons, information on travel modes and their socio demographic information. Data obtained from surveys were aggregated to annual level and weighted in order to obtain PKT/person/year under each socio demographic category. Weightages were estimated using census data in each administrative district. The study came up with important findings; weighted PKT estimations and travel mode distributions in each administrative district. Further, statistical comparisons of PKT estimates among different socio demographic groups and districts were conducted using One-Way Analysis of Variance (ANOVA) test. These findings were key contributions to the existing literature in the country. KEYWORDS: Personal Kilometers of Travel, travel mode distributions, transport planning, policy making, paper-based survey, socio demographic factors, statistical comparisons.

This research looks into the mobility problems that female travelers undergo, with an emphasis on Sri Lankan women. Males and females have different social and economic roles and obligations in most civilizations, and as a result, there are major gender variations in travel and transportation demands. The aim of this research is to investigate the mobility issues of females while traveling. This research analyzes mobility problems of female travelers with special reference to the Western province of Sri Lanka. This research targets to identify the mobility barriers which affect the females’ lifestyle, the problems, and threats females have faced, and the way they go through these problems. The socioeconomic, perspective of people, and travel behavior data were collected from 450 females by using a paper-based questionnaire in August 2021. Ordinal logistic regression analysis and Chi-square test were used to analyze the data. According to the results, sexual harassment while traveling was a significant problem. Among the respondents, 17% of respondents stated that sexual harassment was the most concerning security risk when traveling and 46.8% of female respondents faced sexual harassment when traveling by buses. Based on the types of harassment 26% of females experienced physical harassment as the most frequent harassment type and 25% experienced verbal harassment in public places or public transportation. Majority 42% of the females were strongly stated that they faced sexual harassment problems after dark. Poor maintenance of open public spaces, overcrowded buses/trains, lack of effective/visible police or civil guards, and lack of regulation on transport safety such as men dealing with or taking alcohol/drugs were factors that contribute to sexual harassment by females in public places and transport. The results of this analysis provide valuable insights into the mobility problems of female travelers in day-to-day life due to various reasons. KEYWORDS: Females, Mobility, Ordinal logistic regression, Sexual harassment, Travel

Increasing queue lengths while reducing average vehicle speeds is a notable criterion in intersections with heterogeneous traffic conditions. Such queue lengths vary with different intersection controls. This study aimed to estimate the queue length at un-signalized intersections with heterogeneous traffic conditions. The study was done for un-signalized intersections in Peradeniya and Weliwita, Sri Lanka and the data were collected through video recordings. The queue lengths in an un-signalized intersection with mixed traffic conditions have an instantaneous aggressive variation due to the uncontrolled movements. Thus, a time series analysis with the aid of Vector Auto Regression (VAR) model was used in order to estimate the queue length. Variables considered in this study were arrival flow rate, discharge flow rate, number of conflicts for 15 seconds time intervals as independent variables and queue length at the end of each 15 seconds as the dependent variable. For the modelling, the procedure of “Box-Jenkins” method was followed. After the confirmation of the variables are stationary, Cointegration check and Granger causality tests were done to check the cointegration between variables and the granger causality between variables. Then, VAR models were developed using 80% data from the total data set for both locations. The remaining 20% of the data set was used to validate the model using the MAE, MAPE, and RMSE error values between the actual and predicted queues. Among both models, 0.94 of higher R2 value and Durbin Watson value as 2 was obtained for the developed model using raw variables for Weliwita junction. Furthermore, the observed MAE, MAPE, and RMSE values for Weliwita model were 3,5 and 6%, respectively. Thus, the results of this study can be used to reduce traffic congestion while enhancing the safety of the users at un-signalized intersections in Sri Lanka. KEYWORDS: heterogeneous traffic, queue length, time series analysis, un-signalized intersections.

Pedestrians engaged crashes were increased day by day in the world. There is a high risk of accidents for pedestrians when crossing the road than walking on the road. To minimize the crash rate on pedestrians it is important to know about the risks faced by pedestrians on the road. This study aimed to report pedestrians’ perceptions of risks while walking and crossing the road. A questionnaire survey was carried out to get the data about pedestrians’ perceptions of risks while walking and crossing the road in Matara district. Data were collected with questions with a five-point scale during August and September 2021 from 225 females and 175 males. The collected data were validated by estimating the Cronbach Alpha values and analyzed using chi-square tests and multinomial logistic regression methods. The results of the study were shown the usage of that technical device while walking on the road is the most reported (66.2%) pedestrian risk in the walkways. Whereas crossing the road without using pedestrian crossings is the most reported risk (73%) during the time of crossing the road. The chisquare test results of the survey were indicated that some of the self-reported risks have a significant association with age and gender. Male pedestrians involved with risky behaviours than female pedestrians because male pedestrians have high observed values than the expected values in the reported risks. Age groups, less than 18 years and 18-30 pedestrians were mostly engaged with risky behaviours on the road. Their observed values in the pedestrian risks especially in using technical devices on the road are higher than the observed values compared to other age groups. When the average walking distance of pedestrians per day is increased, accidents happening on pedestrians is also increased. The results of this study would help infrastructure designers to make safer roads. KEYWORDS: crossing, pedestrians, self-reported risks, walking, age, gender

Overtaking slower moving vehicles on the curbside under mix traffic condition is very common in Sri Lanka. The overtaking should never be done from the curbside as a rule of thumb, also rules and regulations regarding the overtaking should be never broken by drivers. Traffic accidents statistics reveal that main cause for serious accidents in Sri Lanka are excessive speed and incorrect overtaking. However, to the best of authors’ knowledge any research about curbside overtaking behavior has not been done so far. Objectives of this study are to investigate self-reported drivers’ overtaking behavior, and to find out drivers’ perspective about current rules and regulations on overtaking. A questionnaire form was developed, and a survey was conducted to collect data among 430 people in Colombo district. Chi–square tests and multinomial logistic regression analysis were done. Chi – square test results showed that among the selected variables, gender, age, occupation, driving license availability, charged a fine or accident due to curbside overtaking are the main factors that affect the curbside overtaking. The results of this study are facilitative to understand characteristics and some reasons behind curbside overtaking. Some methods such as educate public about dangerous overtaking and rules by organizing awareness programs, increasing fine for curbside overtaking, and imposing new laws are suggested to minimize the number of road accidents caused by overtaking slow moving vehicles on the curbside of the road. KEYWORDS: overtaking, drivers’ misbehavior, traffic accidents, road safety, questionnaire survey.

The pavement prediction model forecasts the future PCI ratings based on pavement category, thickness, traffic, pavement life period and existing PCI rating. Nevertheless, with time and inclusion of newer pavement types, there was a need to adjust the prevailing pavement performance models. In addition to, pavements management systems need to develop new models for newer pavement types as well. Some developed pavement performance models in the earlier for the Road Development Authority (RDA) Sri Lanka is used by the roadway segments to predict the future condition and rehabilitations of its network. The available data collections in the roadway agencies in Sri Lanka was used for the research study and the methodology and the analysis section depended on that data collection. Probably we were given the IRI data collections which were done in southern expressway section in Sri Lanka. Based on that data, the analysis part was done for determine the pavement roughness deterioration curves. With a comparison of the developed models, the most suitable model was taken at 95% confidence level with 0.8009 R2 value. This study displays outcomes about of standardizing the present performance models, and creating unused models for the different asphalt forms within the roadway network in Sri Lanka. A comparison of IRI progression with pavement age and traffic volume is also conducted to see if there are major differences between such models developed in other countries. The anticipated expectations condition of the asphalts is utilized in assessing its outstanding benefit life to disappointment, which is of prompt utilize in prescribing future upkeep and recovery necessities for the arrange. KEYWORDS: International Roughness Index, performance model, flexible pavement, rehabilitation