•Implemented road marking treatments positively affected driving behaviour before and throughout the dangerous curves.•Both road markings treatments resulted in a decrease in driving speed, ...regardless of the curve direction (left/right).•Red median conditions affected the speed reduction slightly better compared horizontal warning sign conditions before and throughout the curve.•Based on the results, practical implementation strategy of tested measures is proposed.
Statistics show that horizontal curves, especially those of radii less than 200 m, present an increased road accident risk mainly due to inappropriate speed and failure to maintain proper lateral position. This simulator study aims to analyse how two low-cost road marking measures (red median and horizontal warning signs), alone or combined with a vertical warning sign, affect driver behaviour (driving speed, lateral movement, acceleration/deceleration) before and throughout dangerous horizontal curves on a two-way rural road. With GIS-supported mapping of traffic accidents, we identified the most dangerous curves on the main rural road in Croatia and replicated them on the driving simulator. Based on the driving runs of 43 participants, the study concluded that both measures, used either alone or combined with a vertical warning sign, significantly reduced the speed compared to the control condition (vertical warning sign alone). Additionally, the use of a red median prompted the lateral movement of the vehicle closer to the edge line. The paper also defines the potential use of the measures for dealing with specific types of curve-related accidents.
As part of the traffic control plan, road markings form the traffic surface and provide visual guidance for road users. Since their first application to the present day, road markings have become a ...common element of road infrastructure and one of the basic low-cost safety measures. The aim of this paper is to provide a systematic review of the most significant academic activities to date regarding the influence of longitudinal and transverse road markings as well as road markings for hazard locations (curves, intersections, and rural-urban transitions) on driver’s behaviour and overall road safety. The review includes a total of 71 studies from which are 52 peer-reviewed journal studies, 4 conference proceedings, and 15 professional reports. The studies are, based on their aim, divided into two categories: (1) studies on the impact of road markings on driver behaviour (36 studies) and (2) studies on the impact of road markings on road safety (35 studies).
(1) Background: Due to its high safety potential, one of the most common ADAS technologies is the lane support system (LSS). The main purpose of LSS is to prevent road accidents caused by road ...departure or entrance in the lane of other vehicles. Such accidents are especially common on rural roads during nighttime. In order for LSS to function properly, road markings should be properly maintained and have an adequate level of visibility. During nighttime, the visibility of road markings is determined by their retroreflectivity. The aim of this study is to investigate how road markings' retroreflectivity influences the detection quality and the view range of LSS. (2) Methods: An on-road investigation comprising measurements using Mobileye and a dynamic retroreflectometer was conducted on four rural roads in Croatia. (3) Results: The results show that, with the increase of markings' retroreflection, the detection quality and the range of view of Mobileye increase. Additionally, it was determined that in "ideal" conditions, the minimal value of retroreflection for a minimum level 2 detection should be above 55 mcd/lx/m
and 88 mcd/lx/m
for the best detection quality (level 3). The results of this study are valuable to researchers, road authorities and policymakers.
Traffic signs are an integral part of the traffic control plan and they provide road users with necessary information on the upcoming situation. This paper aims to examine the level of understanding ...of traffic sign imagery used in different countries and to track participants' eye movement when they encounter unfamiliar signs. Tobii eye tracking glasses were used to track gaze differences between familiar and unfamiliar traffic signs. Our findings show that sign characteristics (such as the amount of information on the sign) and the observer's knowledge of the sign meaning have a significant impact on eye behaviour. Signs containing more information (loaded with more content) and unfamiliar to the participant systematically produced the longest overall and average fixations and gazing duration. Given that longer gaze time for unfamiliar traffic signs presents a potential traffic hazard, we evaluated the need for standardization of traffic signs.
•Knowledge of sign meaning relates to the sign information load and simplicity.•Unknown signs produce longer gazing and fixation times which hinders road safety.•Traffic signs should be internationally uniformly standardized and ergonomic.
•The interactions between accident severity levels and traffic signs are identified in state roads.•A seemingly unrelated regression (SUR) model in unbalanced panel data approach is proposed.•The ...seemingly. unrelated regression model addresses the correlation of residuals between different accident severity levels, and the panel data model accommodates the heterogeneity attributed to unobserved factors.•By comparing the pooled, fixed-effects and random-effects SUR models, the random-effects SUR model shows priority to the other two.•The results reveal that different traffic signs cause different accident severity levels, which benefits the policy makers and roadway management departments.
This study intended to investigate the interactions between accident severity levels and traffic signs in state roads located in Croatia, and explore the correlation within accident severity levels and heterogeneity attributed to unobserved factors. The data from 410 state roads between 2012 and 2016 were collected from Traffic Accident Database System maintained by the Republic of Croatia Ministry of the Interior. To address the correlation and heterogeneity, a seemingly unrelated regression (SUR) model in unbalanced panel data approach was proposed, in which the seemingly unrelated model addressed the correlation of residuals, while the panel data model accommodated the heterogeneity due to unobserved factors. By comparing the pooled, fixed-effects and random-effects SUR models, the random-effects SUR model showed priority to the other two. Results revealed that (1) low visibility and the number of invalid traffic signs per km increased the accident rate of material damage, death or injured; (2) average speed limit exhibited a high accident rate of death or injured; (3) the number of mandatory signs was more likely to reduce the accident rate of material damage, while the number of warning signs was significant for accident rate of death or injured.
Lateral support systems in vehicles have a high potential for reduction of lane departure crashes. To profit from their full potential, such systems should function properly in adverse conditions. ...Literature indicates that their accuracy varies between day and night-time. However, detailed quantifications of the systems’ performance in these conditions are rare. The aim of this study is to investigate the differences in detection quality and view range of Mobileye 630 in dry daytime and night-time conditions. On-road tests on four rural road sections in Croatia were conducted. Wilcoxon signed-rank test was used to test the difference between the number of quality rankings while absolute average, average difference and standard deviation were used to analyse the view range. Also, a paired samples t-test was used to test the difference between conditions for each line on each road. The overall results confirm that a significant difference in lane detection quality view range exists between tested conditions. “Medium” and “high” detection confidence (quality level 3 and 2), increased by 5% and 8% during night-time compared to daytime while level 0 (“nothing detected”) decreased by 12%. The view range increased (almost 16% for middle line) during daytime compared to night-time. The findings of this study expand the existing knowledge and are valuable for research and development of machine-vision systems but also for road authorities to optimize the markings’ quality performance.
•Largest eye tracking study of pedestrian conspicuity at night (sample of 115 drivers)•Reflective clothing on pedestrians elicits more active driver eye movements.•Reflective vests can boost ...pedestrian detection distance more than previously thought.•Driver characteristics do not have a major effect on pedestrian detection distance.•Driver’s expectation of pedestrians does not affect pedestrian detection distance.
Pedestrians account for nearly a quarter of all road fatalities in the European Union, with almost half of them occurring at night. The aim of this study is to use eye tracking to analyse how well and from what distance drivers perceive pedestrians wearing different clothing (black or light-coloured clothing, or an orange or yellow retroreflective vest). With the data collected from 115 drivers, this study appears to be the largest eye-tracking study of pedestrian conspicuity at night. The results show that participants noticed pedestrians wearing reflective vests at a distance greater than 200 m, while they only noticed those wearing white, grey or black clothes at a distance of 17–50 m. Participants' gender, age and driving experience did not have a significant impact on the distance at which they perceived pedestrians, suggesting that pedestrian visibility is the key determinant of their safety at night. The obtained results and the innovative application of driver eye tracking in this study provide the basis for further research on pedestrian conspicuity at night.
Advanced Driver Assistance System (ADAS) represents a collection of vehicle-based intelligent safety systems. One in particular, Traffic Sign Recognition System (TSRS), is designed to detect and ...interpret roadside information in the form of signage. Even though TSRS has been on the market for more than a decade now, the available ones differ in hardware and software solutions they use, as well as in quantity and typology of signs they recognize. The aim of this study is to determine whether differences between detection and readability accuracy of market-ready TSRS exist and to what extent, as well as how different levels of “graphical changes” on the signs affect their accuracy. For this purpose, signs (“speed limit” and “prohibition of overtaking”) were placed on a test field and 17 vehicles from 14 different car brands underwent testing. Overall, the results showed that sign detection and readability by TSRS differ between car brands and that even small changes in the design of signs can drastically affect TSRS accuracy. Even in a controlled environment where no sign has been altered, there has been a 5% margin of misread signs.
•Music genre affects driving speed as well as visual scanning of the environment.•No effect of music genre on acceleration/deceleration rate and lateral movement.•Musically more “aggressive” and ...faster songs increased driving errors.
Recently, distractions have been recognized as a significant risk factor in road traffic. This simulator study aims to investigate how different music genres affect the driving behaviour of young drivers and their visual scanning of the environment in urban settings. The genres considered were Croatian pop, foreign pop, classical music, metal, and Balkan folk music, while on one road section there was no music. The research sample consisted of 61 participants (44 males and 17 females) with a mean age of 24.58 years and a mean driving experience of 5.25 years. The influence of music on the drivers’ behaviour was analysed on the basis of the data collected from the driving simulator, eye tracking glasses, and structured observation during driving sessions. It was found that the highest average speed (around 60 km/h) was recorded while the participants were listening to Balkan folk and metal music, while other music genres, as well as the “no music” condition, influenced driving speed in a similar way to one another and the participants drove at 50 km/h on average. Furthermore, the results suggest that the music genre also affects how drivers visually scan the environment (the number of gazes classified as fixations and number of road signs looked at). The findings obtained may be used in road safety work and practical recommendations and further research are discussed.
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