Search results for " transportation"
showing 10 items of 511 documents
High Quality Reconstruction of Dynamic Objects using 2D-3D Camera Fusion
2017
International audience; In this paper, we propose a complete pipeline for high quality reconstruction of dynamic objects using 2D-3D camera setup attached to a moving vehicle. Starting from the segmented motion trajectories of individual objects, we compute their precise motion parameters, register multiple sparse point clouds to increase the density, and develop a smooth and textured surface from the dense (but scattered) point cloud. The success of our method relies on the proposed optimization framework for accurate motion estimation between two sparse point clouds. Our formulation for fusing it closest-point and it consensus based motion estimations, respectively in the absence and pres…
Exploiting Low-Cost 3D Imagery for the Purposes of Detecting and Analyzing Pavement Distresses
2020
Road pavement conditions have significant impacts on safety, travel times, costs, and environmental effects. It is the responsibility of road agencies to ensure these conditions are kept in an acceptable state. To this end, agencies are tasked with implementing pavement management systems (PMSs) which effectively allocate resources towards maintenance and rehabilitation. These systems, however, require accurate data. Currently, most agencies rely on manual distress surveys and as a result, there is significant research into quick and low-cost pavement distress identification methods. Recent proposals have included the use of structure-from-motion techniques based on datasets from unmanned a…
Legibility of Text and Pictograms in Variable Message Signs: Can Single-Word Messages Outperform Pictograms?
2018
The current research shows the advantage of single-word messages in the particular case of variable message signs (VMSs) with a high aspect ratio.Early studies on traffic sign design proposed that pictorial information would advantage equivalent text messages in static signs.We used a driving simulator to present individually 36 VMSs, showing six words (e.g., "congestion") and six danger signs (e.g., congestion traffic sign). In Experiment 1, 18 drivers read aloud the text or orally identified the pictograms as soon as they could correctly do it. In Experiment 2, a different sample of 18 drivers gave a motor response, according to the meaning of the message. We analyzed the legibility dista…
Gender and age distribution of motorcycle crashes in Spain.
2018
This study analysed motorcycle crashes in Spain. Ninety-nine thousand three hundred and four motorcycle crash reports filed in the years 2006-2011 were extracted from the Directorate General of Traffic database of crashes with victims. These data were analysed in terms of gender, age groups, trip purpose, type of crash, speed violation, day of the week, harm caused, use of helmet and psychophysical conditions of the driver to study the characteristics of motorcycle crashes in Spain and to assess the differences between male and female motorcycle drivers in these crashes. Significant differences were found in all the variables considered in the study, which implies gender differences in the …
Angry thoughts in Spanish drivers and their relationship with crash-related events. The mediation effect of aggressive and risky driving
2016
Abstract Several studies have related aggressive and risky driving behaviours to accidents. However, the cognitive processes associated with driving aggression have received very little attention in the scientific literature. With the aim of shedding light on this topic, the present research was carried out on a sample of 414 participants in order to validate the Driver’s Angry Thoughts Questionnaire (DATQ) with a sample of Spanish drivers and to test the hypothesis of the mediation effect of aggressive and risky driving on the relationship between drivers’ angry thoughts and crash-related events. The results showed a good fit with the five-factor model of the questionnaire (Judgmental and …
The Attentional Demand of Automobile Driving Revisited: Occlusion Distance as a Function of Task- Relevant Event Density in Realistic Driving Scenari…
2014
Objective: We studied the utility of occlusion distance as a function of task-relevant event density in realistic traffic scenarios with self-controlled speed. Background: The visual occlusion technique is an established method for assessing visual demands of driving. However, occlusion time is not a highly informative measure of environmental task-relevant event density in self-paced driving scenarios because it partials out the effects of changes in driving speed. Method: Self-determined occlusion times and distances of 97 drivers with varying backgrounds were analyzed in driving scenarios simulating real Finnish suburban and highway traffic environments with self-determined vehicle speed…
Stress-related psychosocial factors at work, fatigue, and risky driving behavior in bus rapid transport (BRT) drivers
2016
Abstract Introduction There is consistent scientific evidence that professional drivers constitute an occupational group that is highly exposed to work related stressors. Furthermore, several recent studies associate work stress and fatigue with unsafe and counterproductive work behaviors. This study examines the association between stress-related work conditions of Bus Rapid Transport (BRT) drivers and risky driving behaviors; and examines whether fatigue is a mechanism that mediates the association between the two. Method A sample of 524 male Bus Rapid Transit (BRT) operators were drawn from four transport companies in Bogota, Colombia. The participants answered a survey which included an…
Can We Study Autonomous Driving Comfort in Moving-Base Driving Simulators? A Validation Study.
2016
Objective: To lay the basis of studying autonomous driving comfort using driving simulators, we assessed the behavioral validity of two moving-base simulator configurations by contrasting them with a test-track setting. Background: With increasing level of automation, driving comfort becomes increasingly important. Simulators provide a safe environment to study perceived comfort in autonomous driving. To date, however, no studies were conducted in relation to comfort in autonomous driving to determine the extent to which results from simulator studies can be transferred to on-road driving conditions. Method: Participants ( N = 72) experienced six differently parameterized lane-change and de…
Relationships of working conditions, health problems and vehicle accidents in bus rapid transit (BRT) drivers
2018
Background The aim of this study was to estimate accident risk rates and mental health of bus rapid transit (BRT) drivers based on psychosocial risk factors at work leading to increased stress and health problems. Methods A cross-sectional research design utilized a self-report questionnaire completed by 524 BRT drivers. Results Some working conditions of BRT drivers (lack of social support from supervisors and perceived potential for risk) may partially explain Bogota's BRT drivers' involvement in road accidents. Drivers' mental health problems were associated with higher job strain, less support from co-workers, fewer rewards and greater signal conflict while driving. Conclusions To preve…
Spanish validation of the mindful organizing scale: A questionnaire for the assessment of collective mindfulness
2018
Abstract Introduction Mindful organizing (also known as collective mindfulness) is a team level construct that is said to underpin the principles of high-reliability organizations (HROs), as it has shown to lead to almost error-free performance. While mindful organizing research has proliferated in recent years, studies on how to measure mindful organizing are scarce. Vogus and Sutcliffe (2007) originally validated a nine-item “Mindful Organizing Scale” but few subsequent validation studies of this scale exist. The present study aimed to validate a Spanish version of the Mindful Organizing Scale. Method The sample included 47 teams (comprising of a total of 573 workers with an average team …