Cyclist efficiency and its dependence on infrastructure and usual speed

Bicyclists are a heterogeneous group, with varying abilities, traffic education and experience. While efficiency was identified as an important factor on utility bicycle trips, it might be traded for experienced safety, for example by choosing different pathways in a given situation, or by relinquishing one’s right of way. In a semi-controlled study with 41 participants, a grouping was made according to self-reported riding speed in relation to other cyclists. The participants cycled twice along a 3 km inner-city route, passing four intersections with different priority rules. The cyclists were free to choose how to negotiate the intersections. Speed and the traffic surroundings were recorded via gps and cameras on the bike of the participant and of a following experimenter. For each cyclist, the ‘base’ speed on undisturbed segments was determined as reference. Based on this, the efficiency in different types of intersections was computed per cyclist group. It turned out that infrastructural aspects, cyclist group and the presence and behaviour of interacting traffic influenced cyclist efficiency. Faster cyclists were delayed more when the infrastructure required a stop regardless of the traffic situation, like at a red traffic light or a stop sign. The members of the so-called ‘comfort cyclists’ group were delayed the most in a roundabout with mixed traffic, where many chose to get off their bike and walk. In a society working for equality of access to the transport system, it is recommended to develop solutions that consider and accommodate the behaviours of different cyclist groups when planning bicycling infrastructure.     

“What Makes a Cooperative Driver?” Identifying parameters of implicit and explicit forms of communication in a lane change scenario

An automated vehicle needs to learn how human road users communicate with each other in order to avoid misunderstandings and prevent giving a negative outward image during interactions. The aim of the present work is to develop an autonomous driving system which communicates its intentions to change lanes based on implicit and explicit rules used by human drivers. To reach this goal, we aimed at gaining a deeper understanding of which aspects of lane change behaviour makes them cooperative from the perspective of other drivers. Therefore a vehicle used various lane change announcement strategies by varying combinations of driving parameters in a static driving simulator. (First study: Start indicator signal, Waittime, lane change duration; Second study: Longitudinal acceleration). It’s impact on the perception and behaviour of other road users was observed in two studies (N = 25 per study). The results showed that the earlier the merging vehicle was indicating its intentions, the more cooperative it was perceived. When turning on the indicator at a later time participants considered it as more cooperative to merge with a slower or faster lane change duration or to wait longer in the lane before starting to move to the other lane. An early longitudinal acceleration when starting to change lanes is perceived more cooperative. These findings can be used to model a lane change strategy based on human behaviour, which will eventually lead to more acceptable and safer interactions between automated and non-automated road users.     

Task-defined associations are mode specific for selection of relevant dimension but mode independent for selection of location mapping

When compatible and incompatible mappings of a location-relevant task are mixed, or a location-relevant task is mixed with a task for which stimulus location is irrelevant, the benefit of the compatible mapping is eliminated for physical locations and enhanced for location words. Two experiments examined the influence of presenting the location information for the mixed conditions in different stimulus modes (physical location or word). Experiment 1 showed that the effects of mixing location-relevant and location-irrelevant tasks on the spatial compatibility and Simon effects are reduced when the location information is presented in different modes for the two tasks. Experiment 2 showed, in contrast, that the mode distinction had little influence on the effects of mixed compatible and incompatible mappings for location-relevant tasks: The compatibility effect was eliminated for physical locations and enhanced for words, as when there is no mode distinction. Thus, when location is relevant for one task and colour for the other, the task-defined associations of locations to responses are mode specific, but when location is relevant for both tasks, the associations are mode independent.     

Surrogate safety indicator for unsignalised pedestrian crossings

ProblemAlthough the road safety situation in Poland is generally improving, the number of accidents at pedestrian crossings has not decreased in the last four years. This paper presents the results of the MOBIS research project, the aim of which was to develop surrogate safety indicators, based on detection of pedestrian-vehicle conflicts using video analysis.MethodPedestrian and vehicle traffic was filmed at two unsignalised pedestrian zebra crossings in Warsaw and Wrocław for over 40 days. Motion trajectories of vehicles and pedestrians were determined based on video processing. Several variables describing pedestrian-vehicle interactions were calculated, such as speed, post-encroachment time, distance between the participants, decelerations, etc. Classification of encounters was based on interactions of pedestrians and vehicles i.e. drivers yielding to pedestrians, vehicles passing just in front of, or behind pedestrians.Results and discussionCriteria for identification of dangerous encounters were selected with the assumption that it should be possible to automate the assessment process. The selected variables were: pedestrian-vehicle passing distance and the vehicle speed at that moment. Other criteria were used in cases of abrupt braking – deceleration exceeding 4 m/s² and vehicle speed. A Dangerous Encounter Index is proposed as a surrogate safety indicator for pedestrian crossings. It relates the occurrence of dangerous events to exposure, defined as the number of pedestrian-vehicle encounters.Practical applicationsThe proposed index shows that crossing two lanes involves more risk than crossing one lane, given similar traffic flow. Some improvement of safety at both types of crossing was observed after active signage involving blinking lights had been introduced. The proposed method is a step towards automation of safety assessment.     

Development and validation of the Drivers’ Emotional Intelligence Inventory (EMOVIAL)

Road fatalities involving young road users have become a global health issue. Although human factors are known to be involved in road fatalities, little research has examined the way in which emotional competencies may affect road accidents. With the aim of filling this gap we describe the development and validation of a scale for measuring emotional intelligence when driving. The EMOVIAL inventory consists of nine items distributed across three dimensions (attention to emotions while driving, clarity of emotions while driving, and emotional regulation while driving). Analysis of its psychometric properties showed it to be valid and reliable. The paper discusses how the scale may be used to improve road safety.     

Risky behaviours associated with traffic crashes among app-based motorcycle taxi drivers in Vietnam

Motorcycle taxi services provide an important mobility option for people in developing countries. With the emergence of new transport technologies, app-based motorcycle taxi services have become increasingly popular in recent years. However, little is known about risky driving behaviours and their association with traffic crashes among app-based motorcycle taxi drivers. Through a survey of 602 app-based motorcycle taxi drivers from three cities in Vietnam, this research aimed to investigate the incidence of risky driving behaviours and their association with driver characteristics and traffic crashes. Using a mobile phone while driving was found to be the most common risky driving behaviour (52%) among app-based motorcycle taxi drivers, followed by neglecting to use turn signals (31%), encroaching car lanes (25%), exceeding the speed limit (21%), running red lights (19%) and carrying more than one passenger (17%). In addition, drivers who were students, or those who worked more than 50 h per week, were found to be more likely to engage in risky driving behaviours. Binary logistic regression modelling showed that neglecting to use turn signals, carrying more than one passenger and smoking while driving was significantly associated with self-reported active crash/fall involvement. Turn signal neglect was also associated with active injury crash/fall involvement. The incidence of risky driving behaviours and associated crash involvement was found to be lower among app-based motorcycle taxi drivers compared with regular motorcyclists, yet the findings still highlight the need for ride-hailing firms to deliver improved education and road safety training for their drivers.     

Intérêts et limites de l’utilisation d’une méthodologie mixte : à propos d’une recherche en psychologie de la santé

Recently, the health social sciences, like some fields of psychology, have progressively adopted qualitative methods, particularly in English-speaking countries. When they come in addition to quantitative methods, they are called “mixed methodologies”. Among other reasons, these approaches suffer nonetheless of a lack of acknowledgement because of a still topical debate opposing the positivist-objectivist and the constructivist paradigms. Another reason to this lack of acknowledgement is due to the fact that several authors explain the use of a mixed methodology according to pragmatic arguments. The authors of this paper briefly present these debates and their pertinence in health psychology research and try to overcome them by showing that it is possible to make mixed methodologies fall within a constructivist approach. Their proposal is exemplified through a research work about organ donation decision led in Switzerland. Actually, this research embed multiple and complex factors that offer an appropriated ground for the use of a mixed methodology, qualitative and quantitative.     

Safety perceptions and reported behavior related to cycling in mixed traffic: A comparison between Brisbane and Copenhagen

This study explores the differences in safety perceptions and reported behavior of cyclists in mixed traffic between an emerging cycling city (Brisbane, Australia) and an established cycling city (Copenhagen, Denmark). Perceptions and reported behavior were retrieved from a custom-designed web-based survey administered among cyclists in the two cities. Elicited items concerned perceived risk of infrastructure layouts, fear of traffic, cycling while distracted, use of safety gear, cycling avoidance due to feeling unsafe, and avoidance to cycle in mixed traffic conditions. The data were analyzed with structural equation models. Results show that, in comparison with cyclists in Copenhagen, cyclists in Brisbane perceive mixed traffic infrastructure layouts as less safe, feel more fear of traffic, and are more likely to adopt cycling avoidance as a coping strategy. Results also show that cyclists in Copenhagen tend to use less helmets and to cycle more while being distracted.     

Temporal fluctuations in driving demand: The effect of traffic complexity on subjective measures of workload and driving performance

Traffic density has been shown to be a factor of traffic complexity which influences driver workload. However, little research has systematically varied and examined how traffic density affects workload in dynamic traffic conditions. In this driving simulator study, the effects of two dynamically changing traffic complexity factors (Traffic Flow and Lane Change Presence) on workload were examined. These fluctuations in driving demand were then captured using a continuous subjective rating method and driving performance measures. The results indicate a linear upward trend in driver workload with increasing traffic flow, up to moderate traffic flow levels. The analysis also showed that driver workload increased when a lane change occurred in the drivers’ forward field of view, with further increases in workload when that lane change occurred in close proximity. Both of these main effects were captured via subjective assessment and with driving performance parameters such as speed variation, mean time headway and variation in lateral position. Understanding how these traffic behaviours dynamically influence driver workload is beneficial in estimating and managing driver workload. The present study suggests possible ways of defining the level of workload associated with surrounding traffic complexity, which could help contribute to the design of an adaptive workload estimator.     

Associations between attention,affect and cardiac activity in a single yoga session for female cancer survivors: An enactive neurophenomenology-based approach

Yoga practice is reported to lead to improvements in quality of life, psychological functioning, and symptom indices in cancer survivors. Importantly, meditative states experienced within yoga practice are correlated to neurophysiological systems that moderate both focus of attention and affective valence. The current study used a mixed methods approach based in neurophenomenology to investigate associations between attention, affect, and cardiac activity during a single yoga session for female cancer survivors. Yoga practice was associated with a linear increase in associative attention and positive affective valence, while shifts in cardiac activity were related to the intensity of each yoga sequence. Changes in attention and affect were predicted by concurrently assessed cardiac activity. Awareness of breathing, physical movement, and increased relaxation were reported by participants as potential mechanisms for yoga’s salutary effects. While yoga practice shares commonalities with exercise and relaxation training, yoga may serve primarily as a promising meditative attention-affect regulation training methodology.