Average impact and important features of onboard eco-driving feedback: A meta-analysis

Eco-driving refers to suites of behavior a driver can engage in to improve fuel economy. The most common strategy used to promote eco-driving is onboard feedback that conveys information about fuel efficiency to the driver. This paper presents a statistical meta-analysis of eco-driving feedback studies in order to determine a weighted estimate of the average impact of feedback on fuel economy and explore potential moderators of its effectiveness, particularly regarding features of the feedback interface design. The main effect of onboard feedback on fuel economy across the final sample of 17 studies and 23 effect sizes was 6.6% improvement. Feedback that included information about both instantaneous and accumulated performance predicted larger effects. Though not statistically significant, trends in relationships between other feedback design features and fuel economy outcomes aligned with study hypotheses. Length of feedback intervention negatively related to effects, and pairing feedback with instructions or rewards predicted larger effects.     

Cyclist strategies and behaviour at intersections. Conscious and un-conscious strategies regarding positioning

Severe and even fatal accidents between cyclists and motor vehicles commonly occur at intersections. Many of these accidents occur with right-turning vehicles, with drivers not observing an adjacent cyclist. Few structured investigations exist regarding the interaction between cyclist and motor vehicle, and factors in need of study are how infrastructure and vehicle properties affect human decision-making and cycling behaviour. Therefore, a bicycle simulator study was performed, where vehicle type, presence of lane markings and lane width were systematically varied in a scenario with a cyclist approaching a vehicle from behind, at a signalized city intersection. 33 participants cycled through 8 intersection variants each. Data on cycling trajectories, stopping points and speed was coupled with survey data from the participants, and semantically categorized verbal responses to questions regarding strategy for choice of stopping point. Results show that all three factors (vehicle type, lane markings and available vehicle-adjacent space) significantly affects cyclists’ behaviour and conscious strategies. Participants were more cautious in the presence of a truck than a car, reflected in choice of position when cycling and stopping, and in explicit verbalisations regarding perilous aspects of the situation and their conscious and strategic choice of positioning. Available lateral space also affected stop positions and feeling of safety (expressed verbally). Presence of bicycle lane markings made the cyclists inclined to continue into the space to the right of the vehicle. This was revealed by their positioning and speed, and also apparent in the verbal expressions, especially the positive remarks on the situation and conditions. However, the perceived comfort with lane markings present was actually lower than when they were missing. Cyclist type (slow, moderate, or fast) matters with the self-reported faster cyclists being more prone to stop to the right than the slower one.     

Environnement psycho-technologique (EPT) et comportements d’apprentissage avec les technologies (CAT) : developpement et adaptation française de deux mesures

The 4th industrial revolution and the omnipresence of technologies have largely modified the work context and more specifically the learning process. We postulate the emergence of a new psycho-technological environment, which is characterized by more opportunities to learn and more accessible technologies. To our knowledge, no measurement can capture the perception of psycho-technological environment (PTE) and learning behaviors with technologies (LBT). The aim of this study is therefore to compensate for this lack of tools with the development of French-language. Two studies that combine 389 students were conducted. In the first study, based on a sample of 151 students, two scales were developed via an explanatory factorial analysis. In the second study, based on a sample of 238 students, a confirmatory factorial analysis confirmed the psychometric qualities of our scales. This first validation study shows good validity and fiability with the good psychometric qualities of our scales.     

Semi-automated versus highly automated driving in critical situations caused by automation failures

The purpose of this study was to examine the effects of vehicle automation and automation failures on driving performance. Previous studies have revealed problems with driving performance in situations with automation failures and attributed this to drivers being out-of-the-loop. It was therefore hypothesized that driving performance is safer with lower than with higher levels of automation. Furthermore, it was hypothesized that driving performance would be affected by the extent of the automation failure. A moving base driving simulator was used. The design contained semi-automated and highly automated driving combined with complete, severe, and moderate deceleration failures. In total the study involved 36 participants. The results indicate that driving performance degrades when the level of automation increases. Furthermore, it is indicated that car drivers are worse at handling complete than partial deceleration failures.     

Transition patterns of driving style from a traditional driving environment to a connected vehicle environment: A case of an extra-long tunnel road

To provide a better understanding of individual driver’s driving style classification in a traditional and a CV environment, spatiotemporal characteristics of vehicle trajectories on a road tunnel were extracted through a driving simulator-based experiment. Speed, acceleration, and rate of acceleration changes are selected as clustering indexes. The dynamic time warping and k-means clustering were adopted to classify participants into different risk level groups. To assess the driver behavior benefits in a CV environment, an indicator BI (behavior indicator, BI) was defined based on the standard deviation of speed, the standard deviation of acceleration, and the standard deviation of the rate of acceleration change. Then, the index BI of each driver was calculated. Furthermore, this paper explored driving style classification, not in terms of traditional driving environment, but rather the transition patterns from a traditional driving environment to a CV environment. The results revealed that inside a long tunnel, 80 % of drivers benefited from a CV environment. Moreover, drivers might need training before using a CV system, especially female drivers who have low driving mileage. In addition, the results showed that the driving style of 69 % of the drivers’ transferred from a high risk-level to a low risk-level when driving in a CV environment. The study results can be expected to improve driving training education programs and also to provide a valuable reference for developing individual in-vehicle human-machine interface projects and other proactive safety countermeasures.     

Handing control back to drivers: Exploring the effects of handover procedure during transitions from Highly Automated Driving

The operational capabilities of automated driving features are limited and sometimes require drivers’ intervention through a transition of control. Assistance at an operational level might be extremely beneficial during transitions but the literature lacks evidence on the topic. A simulator study was conducted to investigate the potential impacts that lateral assistance systems might have while the Automated Driving System (ADS) hands back control to the driver. Results showed that drivers benefitted from a strong Lane Keeping Assist during the first phase of the transfer, helping them to keep the lane centre. However, assisting the drivers at an operational level did not enhance their capability of addressing a more complex task, presented as a lane change. In fact, it was more task-specific assistance (Blind-spot assist) that allowed drivers to better cope with the tactical decision that the lane change required. Moreover, longer exposure to lane-keeping assist systems helped them in gaining awareness of the surrounding traffic and improved the way drivers interacted with the Blind-spot assist.     

What happens when drivers of automated vehicles take over control in critical lane change situations?

According to legislation, take-overs initiated by the driver must always be possible during automated driving. For example, when drivers mistrust the automation to handle a critical and hazardous lane change, they might intervene and take over control while the automation is performing the maneuver. In these situations, drivers may have little time to avoid an accident and can be exposed to high lateral forces. Due to lacking research, it is yet unknown if they recognize the criticality of the situation and how they behave and perform to manage it. In a driving simulator study, participants (N = 60) accomplished eight double lane changes to evade obstacles in their lane. Time-to-collision and traction usage were varied to establish different degrees of objective criticality. To manipulate these parameters as required, participants were triggered to take over control by an acoustic cue. This setting shows what might happen if drivers disable the automation and complete the maneuver themselves. The results of the experiment demonstrate that drivers rated objectively more critical driving situations as more critical and responded to the hazard very fast over all experimental conditions. However, their behavior was more extreme with respect to decelerating and steering than necessary. This impaired driving performance and increased the risk of lane departures and collisions. The results of the experiment can be used to develop an assistance system that supports driver-initiated take-overs.     

Affective atmospheres of weapons technologies: The case of battle drones,combat fighters and bodies in contemporary German geopolitics

Using the example of the defense and security sector at the Innovation and Leadership in Aerospace aviation fair in Berlin, this paper interrogates how the presentation of weapons technologies at German security and aviation fairs produces a/effects that influence the body and serve to legitimize political decisions. It examines to what extent the body becomes the site of geopolitical negotiation via affective atmospheres and how different scales interact within this process. First, I argue that affective connections between weapons technologies and spectators are essential for legitimizing warfare technologies. Second, I argue that affects of weapons technologies are subject to ambivalence and ambiguity, and that they are to be understood as entangled with other affects in the same body. Third, I argue that affects become effective across material and spatial scales. Drawing on geographic work on affective atmospheres, debates in intimate geopolitics and feminist science and technology studies, the paper contributes to critical geopolitics by unpacking the role of affective dimensions in naturalizing the development and acquisition of weapons technologies. In doing so, it also contributes to debates on the methodological operationalization of theories of affect and to emotional geographies of (in)security.     

L’avis du CCNE no 126 (15 juin 2017) sur les demandes sociétales de recours à l’assistance médicale à la procréation : un pas en avant et deux en arrière…

On June 15, 2017, the National Consultative Ethics Committee released an opinion in favour of the extension of medically assisted procreation (MAP) to lesbian couples and single women. This opinion recommends a reversal of the medical model, which serves as the starting point for the regulatory framework concerning MAP, and expresses its support to social and family evolutions. Nonetheless this liberal and progressive stand could be a mere smokescreen, if it does not result in any meaningful implementation due to practical hindrances; moreover, this seemingly progressive stand could be questioned in view of the conservative position expressed on the issues of surrogacy and oocyte self-preservation by the committee in the same opinion.     

The estimation of vehicle speed and stopping distance by pedestrians crossing streets in a naturalistic traffic environment

The ability to estimate vehicle speed and stopping distance accurately is important for pedestrians to make safe road crossing decisions. In this study, a field experiment in a naturalistic traffic environment was conducted to measure pedestrians’ estimation of vehicle speed and stopping distance when they are crossing streets. Forty-four participants (18–45 years old) reported their estimation on 1043 vehicles, and the corresponding actual vehicle speed and stopping distance were recorded. In the speed estimation task, pedestrians’ performances change in different actual speed levels and different weather conditions. In sunny conditions, pedestrians tended to underestimate actual vehicle speeds that were higher than 40 km/h but were able to accurately estimate speeds that were lower than 40 km/h. In rainy conditions, pedestrians tended to underestimate actual vehicle speeds that were higher than 45 km/h but were able to accurately estimate speeds ranging from 35 km/h to 45 km/h. In stopping distance estimation task, the accurate estimation interval ranged from 60 km/h to 65 km/h, and pedestrians generally underestimated the stopping distance when vehicles were travelling over 65 km/h. The results show that pedestrians have accurate estimation intervals that vary by weather conditions. When the speed of the oncoming vehicle exceeded the upper bound of the accurate interval, pedestrians were more likely to underestimate the vehicle speed, increasing their risk of incorrectly deciding to cross when it is not safe to do so.