Papers by Sunanda Dissanayake
International Conference on Transportation and Development 2022
Motorists generally follow the guidance provided by pavement markings, which are normally marked ... more Motorists generally follow the guidance provided by pavement markings, which are normally marked in coincidence with the longitudinal construction joints, when the markings are necessary. At some locations, however, there may be a difference between joints and markings, which may lead the motorists to follow joints instead of pavement markings. In the absence of detailed research on this topic, an effort was made in this study to evaluate the effects of unmatched longitudinal construction joints and pavement markings on the lateral positioning of vehicles. Sites with such characteristics were identified, and detailed data were collected at selected sites, using video camera techniques to capture movements of vehicles for longer durations. The video tapes were later reduced to extract necessary information. Distance from the pavement edge to the centerline of each vehicle, vehicle type, presence of vehicles in the adjacent lane, traffic volume, weather conditions, and vehicle movemen...
The percentage of the United States population aged 65 years or older is increasing rapidly. Stat... more The percentage of the United States population aged 65 years or older is increasing rapidly. Statistics show this age group was 14.9 percent of the population in 2015 and is expected to be 20.7 to 21.4 percent for the years 2030–2050. Kansas has similar statewide trends with its aging population. Therefore, identifying issues, concerns, and factors associated with highway safety of older drivers in Kansas is necessary and useful. The Kansas Crash Analysis and Reporting System (KCARS) database maintained by the Kansas Department of Transportation was used in this study to identify older-driver crash characteristics, compare older drivers with all drivers, and develop crash severity models.
The available knowledge and studies which have been carried out on setting speed limits for Sri L... more The available knowledge and studies which have been carried out on setting speed limits for Sri Lankan road ways are very limited. Speed limit, on a given roadway, is a much important factor for road users, because that decides the travel time. This research attempts to evaluate the applicability of speed limits for Sri Lankan road network and develop a methodology for setting up speed limit for selected road section. In the selection of road sections for this research, the scope was limited to straight road sections in flat terrains in sub-urban areas and other characteristics such as shoulder conditions, roadside development and etc pretty much equal. Then, the sample speed data was collected on selected road sections according to the vehicle category. The collected data was processed and compared with existing speed limits. Besides, a questionnaire survey was carried out in order to find out drivers' knowledge and attitude about speed limits on those selected road sections. A...
Safe and efficient flow of traffic through work zones must be established by improving work zone ... more Safe and efficient flow of traffic through work zones must be established by improving work zone conditions. Therefore, identifying the factors associated with the severity and the frequency of work zone crashes is important. According to current statistics from the Federal Highway Administration, 2,372 fatalities were associated with motor vehicle traffic crashes in work zones in the United States during the four years from 2010 to 2013. From 2002 to 2014, an average of 1,612 work zone crashes occurred in Kansas each year, making it a serious concern in Kansas. Objectives of this study were to analyze work zone crash characteristics, identify the factors associated with crash severity and frequency, and to identify recommendations to improve work zone safety. Work zone crashes in Kansas from 2010 to 2013 were used to develop crash severity models. Ordered probit regression was used to model the crash severities for daytime, nighttime, multi-vehicle and single-vehicle work zone crashes and for work zones crashes in general. Based on severity models, drivers from 26 to 65 years of age were associated with high crash severities during daytime work zone crashes and driver age was not found significant in nighttime work zone crashes. Use of safety equipment was related to reduced crash severities regardless of the time of the crash. Negative binomial regression was used to model the work zone crash frequency using work zones functioned in Kansas in 2013 and 2014. According to results, increased average daily traffic (AADT) was related to higher number of work zone crashes and work zones in operation at nighttime were related to reduced number of work zone crashes. Findings of this study were used to provide general countermeasure ideas for improving safety of work zones.
International Conference on Transportation and Development 2020, 2020
Abstracts, 2018
The threat towards the pedestrian safety near the school zones has been increased rapidly compare... more The threat towards the pedestrian safety near the school zones has been increased rapidly compared to the other locations. Insecure situation within school zones can be generated through risky pedestrian behavior as well as the road side condition. This study attempts to obtain a relationship between the pedestrian behavior and road side condition. Four schools in a semi urben city in a developing country were selected based on their locations (whether close to a major road or off from major road) and the presence of special features such as surface crossings, overhead bridges, intersections etc. Each school zone was divided in to four sub zones with 10 m of length. In order to find the relationship between the pedestrian behavior and road condition, video surveys and road inventory surveys were conducted at each selected school zone. Video recordings were analyzed under five criteria: (1) not using walking zones, (2) running on the road, (3) crossing road without using the pedestrian crossing, (4) illegally parked vehicles, (5) overtaking vehicles on the pedestrian crossing) to come up with a behavior risk index for each school zone. Number of vulnerable incidents related to each criterion was obtained through direct observation of video recordings and a weighting method was used to determine the combined effect of several criteria and thereby the behavior risk index for each sub zone was calculated. Road inventory data were analyzed under 8 criteria: (1) pedestrian surface crossing, (2) pedestrian overpass or underpass, (3) no on street parking, (4) no road intersections, (5) sidewalks, (6) no left turns, (7) standard width of lane, (8) safety fence, to come up with an index for the road risk. In order to find the road risk the percentage of crash reduction due to the presence of each criterion was taken into account and thereby, the road risk index related to each sub zone was calculated. It was found that there is an exponential relationship between road risk and behavior risk. When the risk of road factors is increasing the behavior of the pedestrians is being risky and thereby the behavior risk is increased. But the increment rate of behavior risk is decreasing with the road risk and after a certain point the behavior risk of pedestrians won’t be increased even though the road is worst.
Many research studies have analyzed crash data in the past in order to identify various factors c... more Many research studies have analyzed crash data in the past in order to identify various factors contributing to older driver over-involvement in crashes. However, it is also necessary to identify other types of safety- related information which cannot be extracted from crash data, such as exposure to different weather and road conditions, difficulties associated with vehicle maneuvering, modifications made to driving patterns, etc., which might be playing a significant role in older-driver safety. Therefore, a questionnaire was prepared and a survey was conducted to identify those issues and difficulties highlighted in crash data. Based on the responses, a detailed examination was done to understand different behavioral changes in older drivers with respect to various conditions. Based on the survey results, it was found that most of the older drivers have more than fifty years of driving experience and their seat belt usage was also found to be high. Left turns appear to be the most challenging maneuvering task. Analysis based on age revealed that level of difficulty associated with older drivers increases with age, and similarly, preference to avoiding demanding conditions, such as snowy weather, nighttime driving, and use of freeways also increases with aging. Drivers older than 70 years were highly involved in crashes and those with elevated income levels and education had higher involvement in crashes. Older male drivers indicated higher levels of difficulties in stopping, stopped waiting to turn, or slowing down situations. On the other hand, females showed higher levels of difficulty associated with identifying speeds and distance of oncoming traffic compared to males. Findings of this study could be used to develop more focused programs towards improving older driver safety.
Unlicensed young drivers’ involvement in crashes in the United States (U.S.) and the risk factors... more Unlicensed young drivers’ involvement in crashes in the United States (U.S.) and the risk factors associated with crashes involving these drivers have not been fully explored. Few studies provide evidence of fatal crash involvement of young unlicensed drivers. This study investigates characteristics and contributory causes of unlicensed young driver crashes that occurred in Kansas, using crash data obtained from the Kansas Department of Transportation (KDOT). In this study, the age range of drivers from 15 years to 24 years was investigated. A binary logistic regression model was developed to investigate unlicensed young driver injury severity. There were 5,781 young unlicensed driver crashes, representing 3.61% of all young drivers’ crashes, during the five-year period considered in this study. A total of 19 young unlicensed driver-involved fatal crashes occurred during the period. According to the coefficients of the logistic model, seat-belt restrained, unlicensed young drivers w...
The effect of vehicle color on crash involvement has been an interesting topic for several decade... more The effect of vehicle color on crash involvement has been an interesting topic for several decades; however, the effect of a vehicle’s color on its visibility to drivers has not been studied in detail, especially at rural intersections. There has been some speculation that the combination of vehicle color and background environment can cause a camouflage effect on a vehicle’s visibility for drivers stopped at an intersection. In this research, a stopped vehicle was simulated at a rural intersection in Kansas, where a large number of crashes have occurred. Various vehicles with different colors approaching from eastbound and westbound directions under different daytime light conditions were shown to participants. Response times of participants to identify the approaching vehicles were measured for each vehicle color under different conditions. The collected data were analyzed using an Analysis of Variance (ANOVA) test to determine whether there is a difference between the mean respon...
Although extensive research has been conducted on urban freeway capacity estimation methods, mini... more Although extensive research has been conducted on urban freeway capacity estimation methods, minimal research has been carried out for rural highway sections, especially sections within work zones. This study attempted to fill that void for rural highways in Kansas, by estimating capacity of rural highway work zones in Kansas. Six work zone locations were selected for data collection and further analysis. An average of six days' worth of field data was collected, from mid-October 2013 to late November 2013, at each of these work zone sites. Two capacity estimation methods were utilized, including the Maximum Observed 15-minute Flow Rate Method and the Platooning Method divided into 15-minute intervals. The Maximum Observed 15-minute Flow Rate Method provided an average capacity of 1469 passenger cars per hour per lane (pcphpl) with a standard deviation of 141 pcphpl, while the Platooning Method provided a maximum average capacity of 1195 pcphpl and a standard deviation of 28 pcphpl. Based on observed data and analysis carried out in this study, the suggested maximum capacity can be considered as 1500 pcphpl when designing work zones for rural highways in Kansas. This proposed standard value of rural highway work zone capacity could be utilized by engineers and planners so that they can effectively mitigate congestion at or near work zones that would have otherwise occurred due to construction/maintenance. 17. Key Words capacity estimation-rural work zones-work-zone capacity 18. Distribution Statement No restrictions. 19. Security Classification (of this report) Unclassified. 20. Security Classification (of this page) Unclassified.
Journal of the Transportation Research Forum
The Highway Safety Manual (HSM) provides models and methodologies for safety evaluation and predi... more The Highway Safety Manual (HSM) provides models and methodologies for safety evaluation and prediction of safety performance of various types of roadways. However, predictive methods in the HSM are of limited use if they are not calibrated for local conditions. In this study, calibration procedures given in the HSM were followed for rural segments and intersections in Kansas. Results indicated that HSM overpredicts fatal and injury crashes and underpredicts total crashes on rural multilane roadway segments in Kansas. Therefore, existing safety performance functions (SPFs) must be adjusted for Kansas conditions, in order to increase accuracy of crash prediction. This study examined a way to adjust HSM calibration procedures by development of new regression coefficients for existing HSM-given SPF. Final calibration factors obtained through modified SPFs indicated significant improvement in crash prediction for rural multilane segments in Kansas. Additionally, obtained calibration fact...
University. The contents of this paper reflect the views of the author(s), who are responsible fo... more University. The contents of this paper reflect the views of the author(s), who are responsible for the facts and accuracy of the information presented herein.
University. The contents of this paper reflect the views of the author(s), who are responsible fo... more University. The contents of this paper reflect the views of the author(s), who are responsible for the facts and accuracy of the information presented herein.
Part of the Civil Engineering Commons This Article is brought to you for free and open access by ... more Part of the Civil Engineering Commons This Article is brought to you for free and open access by the Mid-America Transportation Center at DigitalCommons@University of Nebraska-Lincoln. It has been accepted for inclusion in Final Reports & Technical Briefs from Mid-America Transportation Center by an authorized
Motor vehicle crashes are one of the leading causes of death among young Americans. They also exp... more Motor vehicle crashes are one of the leading causes of death among young Americans. They also experience higher percentage of single vehicle, Run-off-the-road (ROR) crashes compared to other drivers. When looking at the methods of improving the alarming death rate of young drivers, it is important to identify the determinants of higher crash and injury severity. With that intention, the study described in this paper developed the models to identify the factors that are influential in making an injury severity difference to young drivers involved in ROR crashes. Since the outcome of the models, crash severity, is of discrete nature, logistic regression was identified as the most suitable approach and a set of sequential binary logistic regression models was developed to identify the influential factors. The intention was to predict the crash severity outcome of single vehicle ROR crashes involving young drivers. The developed models were validated and the accuracy was tested by using...
Motorists generally follow the guidance provided by pavement markings, which are normally marked ... more Motorists generally follow the guidance provided by pavement markings, which are normally marked in coincidence with the longitudinal construction joints, when the joints are necessary. At some locations, however, there may be a mismatch between joints and markings, which may lead the motorists to follow joints instead of pavement markings. In the absence of detailed studies on this topic, an effort was made in this study to evaluate the effects of unmatched longitudinal construction joints and pavement markings on the lateral positioning of vehicles. Sites with such characteristics were identified, and detailed data were collected at one of the sites, using video camera technique to capture movements of vehicles for longer durations. The video tapes were later reduced to extract necessary information. Distance to the centerline of each vehicle, vehicle type, presence of vehicles in the adjacent lane, traffic volume, and vehicle movement were the main data parameters gathered while ...
Most city centers in developing countries have heavy pedestrian flows. Even when there are suffic... more Most city centers in developing countries have heavy pedestrian flows. Even when there are sufficient pedestrian road crossing facilities, pedestrians follow illegal road crossing patterns creating life threats and disturbing the smooth traffic flow. The primary objective of this research was to evaluate the most influencing attributes that predispose to illegal road crossings. Current research exemplifies the effectiveness of conjoint analysis (CA) in evaluating the most influencing attributes. CA is a multivariate technique used to understand how respondents develop preference for products or services. Results of the CA could be used to interpret relative importance of each selected attribute. The accuracy of the CA is improved by selecting the most appropriate attributes and mutually independent levels for those attributes. Available literature suggests illegal road crossings are governed by two factors: psychological characteristics and physical environment. Familiarity of the l...
Advances in transportation studies, 2003
The safety of left turning vehicles from driveways onto major arterials carrying high traffic vol... more The safety of left turning vehicles from driveways onto major arterials carrying high traffic volumes is of particular importance. Left turn movement at such locations could be accommodated either through direct left turns (DT) or right turns followed by U-turns (RUT). The work summarized in this paper evaluated the effects of these 2 alternatives where the safety comparison using traffic conflicts is described. This was achieved through field data collection of traffic and traffic conflict data at locations where 1 or both of the 2 alternative treatments were utilized. Two types of conflict rates, conflicts per hour and conflicts per thousand, involved vehicles were used in comparing the safety of the 2 left turning alternatives. Average number of conflicts per hour for DT and RUT were 6.35 and 4.20, respectively. When data was separated into peak or non-peak periods, average peak hourly conflicts were 7.01 and 3.98 for DT and RUT, respectively. When average number of conflicts per...
Advances in transportation studies, 2007
The purpose of this study was to estimate seat belt effectiveness in preventing fatal and nonfata... more The purpose of this study was to estimate seat belt effectiveness in preventing fatal and nonfatal injuries to motor vehicle occupants when they are involved in crashes. The double pair comparison method was used and the estimations were based on police reported highway crash data of the state of Kansas in the United States. Two vehicle groups were considered: passenger cars and other passenger vehicles (vans and pickup trucks). Only front seat occupants who were older than 14 years of age were considered in the analysis. Based on estimations, seat belts were found to be 53% effective in reducing fatal injuries to front seat occupants in passenger cars. In other passenger vehicles, effectiveness of seat belts in reducing fatal injuries is 57%. As far as nonfatal injuries are concerned, seat belts are 52% and 42% effective in reducing incapacitating and non-incapacitating injuries respectively in passenger cars. It was also found that seat belts are 34% effective in reducing possible...
Uploads
Papers by Sunanda Dissanayake