Automated driving has the potential to improve the safety and efficiency of future traffic and to extend elderly peoples' driving life, provided it is perceived as comfortable and joyful and is ...accepted by drivers. Driving comfort could be enhanced by familiar automated driving styles based on drivers' manual driving styles. In a two-stage driving simulator study, effects of driving automation and driving style familiarity on driving comfort, enjoyment and system acceptance were examined. Twenty younger and 20 older drivers performed a manual and four automated drives of different driving style familiarity. Acceptance, comfort and enjoyment were assessed after driving with standardised questionnaires, discomfort during driving via handset control. Automation increased both age groups' comfort, but decreased younger drivers' enjoyment. Younger drivers showed higher comfort, enjoyment and acceptance with familiar automated driving styles, whereas older drivers preferred unfamiliar, automated driving styles tending to be faster than their age-affected manual driving styles.
Practitioner Summary: Automated driving needs to be comfortable and enjoyable to be accepted by drivers, which could be enhanced by driving style individualisation. This approach was evaluated in a two-stage driving simulator study for different age groups. Younger drivers preferred familiar driving styles, whereas older drivers preferred driving styles unaffected by age.
While research has shown that limited-range electric vehicles (EVs) satisfy the range needs of a sizeable share of the driving population, car buyers seem to prefer vehicles with high available ...range. The objective of the present research was to advance understanding of the factors that influence the range preferences of potential EV customers who had the opportunity to test an EV. Data from 79 participants who had driven an EV for 3 months was assessed in a field study setting. Range preferences of those users were found to be substantially higher than their average range needs. Regression analyses indicated that higher average range needs, higher range of the driver′s familiar combustion vehicle (CV), and greater experienced range anxiety were related to higher range preferences. Furthermore, we found that range preferences decreased over the first 3 months of EV use. Finally, indicators of average range needs were more strongly associated with range preferences as EV experience increased. Thus, only customers with EV experience seem to rely on accurate estimates of their range needs when constructing their range preferences. Implications for strategies aimed at enhancing customer appraisal of limited range mobility and determining optimal EV range are discussed.
•Range preferences are above average, but similar to weekly maximum range needs.•Range preferences decrease with practical electric vehicle (EV) experience.•Range preferences are more strongly related to average range needs in experienced EV users.•Familiar combustion car range seems to be a reference point for range preferences.•Experienced range anxiety is related to higher range preferences.
Objective:
The objective for this study was to investigate the effects of prior familiarization with takeover requests (TORs) during conditional automated driving on drivers’ initial takeover ...performance and automation trust.
Background:
System-initiated TORs are one of the biggest concerns for conditional automated driving and have been studied extensively in the past. Most, but not all, of these studies have included training sessions to familiarize participants with TORs. This makes them hard to compare and might obscure first-failure-like effects on takeover performance and automation trust formation.
Method:
A driving simulator study compared drivers’ takeover performance in two takeover situations across four prior familiarization groups (no familiarization, description, experience, description and experience) and automation trust before and after experiencing the system.
Results:
As hypothesized, prior familiarization with TORs had a more positive effect on takeover performance in the first than in a subsequent takeover situation. In all groups, automation trust increased after participants experienced the system. Participants who were given no prior familiarization with TORs reported highest automation trust both before and after experiencing the system.
Conclusion:
The current results extend earlier findings suggesting that prior familiarization with TORs during conditional automated driving will be most relevant for takeover performance in the first takeover situation and that it lowers drivers’ automation trust.
Application:
Potential applications of this research include different approaches to familiarize users with automated driving systems, better integration of earlier findings, and sophistication of experimental designs.
Objective:
The objective of the present research was to increase understanding of the phenomenon of range anxiety and to determine the degree to which practical experience with battery electric ...vehicles (BEVs) reduces different levels of range anxiety.
Background:
Limited range is a challenge for BEV users. A frequently discussed phenomenon in this context is range anxiety. There is some evidence suggesting that range anxiety might be a problem only for inexperienced BEV drivers and, therefore, might decrease with practical experience.
Method:
We compared 12 motorists with high BEV driving experience (M = 60,500 km) with 12 motorists who had never driven a BEV before. The test drive was designed to lead to a critical range situation (remaining range < trip length). We examined range appraisal and range stress (i.e., range anxiety) on different levels (cognitive, emotional, and behavioral).
Results:
Experienced BEV drivers exhibited less negative range appraisal and range anxiety than inexperienced BEV drivers, revealing significant, strong effects for all but one variable.
Conclusion:
Hence, BEV driving experience (defined as absolute kilometers driven with a BEV) seems to be one important variable that predicts less range anxiety.
Application:
In order to reduce range anxiety in BEV drivers even when there is a critical range situation, it is important to increase efficiency and effectiveness of the learning process.
In the near future, more vehicles will have automated functions. The traffic system will be a shared space of automated and manually driven vehicles. In our study we focused on the perspective of ...vulnerable road users, namely pedestrians, in cooperative situations with automated vehicles. Established communication methods, such as eye-contact between pedestrians and drivers, may no longer work when automated vehicles represent the interaction partner. Therefore, we evaluated several human-machine-interfaces (HMI) in order to implement smooth and comfortable communication. We conducted a two-stage study consisting of an explorative focus group discussion with naïve pedestrians (n = 6), followed by an experimental video simulation study (n = 25) based on the results of the focus group discussion. From the focus group we sought member opinion about various HMI, upon presentation of acoustic and visual communication systems such as projections, displays and LED light strips, in addition to portable communication systems, specifically smart watches. On the basis of the focus group discussion, an evaluation criteria was derived. For the video simulation study, HMI designs were created with variations in position, type and coding of the message, and technology. These were assessed by 25 subjects according to the focus discussion derived evaluation criteria: recognizability, unambiguousness, interaction comfort and intuitive comprehensibility. The results show that direct instructions to cross the street are preferred over status information of the vehicle and that large-scale text-based messages from the vehicle to the pedestrian, deliver better results. Design recommendations for HMIs for communication between automated vehicles are derived, and the extent external HMIs may supplement informal communication strategies such as vehicle movement or braking maneuvers, is discussed.
•Design criteria for pedestrian-automation interaction.•Assessment of valuable HMI variations.•Recommendations for HMI developers.
•Comfort of automated lane changes, accelerations and decelerations was analyzed.•For lane changes, low jerks and early motion feedback are advisable.•In direct comparison, deceleration mirroring ...manual behavior is favored least.•Symmetrical accelerations are experienced as more comfortable.•The analyzed personality traits do not seem to have a big influence on preferences.
As technical realization of highly and fully automated vehicles draws closer, attention is being shifted from sheer feasibility to the question of how an acceptable driving style and thus comfort can be implemented. It is increasingly important to determine, how highly automated vehicles should drive to ensure driving comfort for the now passive drivers. Thus far, only little research has been conducted to examine this issue. In order to lay a basis on how automated vehicles should drive to ensure passenger comfort, different variations of three central maneuvers were rated and analyzed. A simulator study (N = 72) was conducted in order to identify comfortable driving strategies. Three variations of lane changes, accelerations and decelerations were configured by manipulating acceleration and jerk, and thus the course of each maneuver. Furthermore, the influence of personality traits and self-reported driving style on preferences of differently executed automated maneuvers was analyzed. Results suggest keeping acceleration and jerk as small as possible for acceleration maneuvers. For lane changes, both small accelerations as well as an early motion feedback are advisable. Interestingly, decelerating as a manual driver would is rejected compared to two artificial alternatives. Moreover, no influence of personality traits on maneuver preference was found. Only self-reported driving style had a marginal effect on participants’ preferences. In conclusion, a recommendation for an automated driving style can be given, which was perceived as comfortable by participants regardless of their personality.
•Experience with battery electric vehicles (BEVs) is important for BEV acceptance.•BEV inexperienced and experienced drivers differ in BEV evaluation and acceptance.•Evaluation of BEV attributes ...predicts attitudinal and behavioral acceptance of BEVs.•Subjective norm is of high relevance for BEV purchase intentions.•Providing direct short-term BEV experience may be a fruitful marketing strategy.
Battery electric vehicles (BEVs) can contribute to the realization of more sustainable mobility systems. The actual adoption rate however of BEVs in Germany remains low, and strategies for enhancing BEV acceptance are required. Providing direct experience can, for instance, help to overcome prejudices relating to relatively new products, with this being a potential marketing strategy. The present research contributes to the question of what role direct experience plays in acceptance of BEVs.
Two studies were conducted to address the relationship between these variables: (1) an online survey (N=286) and (2) a 24-h field test (N=30). Both studies showed several experience-based differences in evaluations of BEV attributes, attitude and purchase intention, with most BEV attributes being evaluated more positively when people had BEV experience. Path analyses revealed a direct experience effect on purchase intention in the online study. Findings from the 24-h field test, showed effects of BEV experience on BEV attributes and attitudes, but no BEV experience effect for purchase intention was found. Based on the results of both studies, we can conclude that practical (and also short-term) experience with BEVs has the potential to change the evaluation of BEVs and psychological factors relevant for determining behavioral intention. As many effects were positive, providing short-term BEV experience to enhance acceptance has the potential to change BEV evaluation as well as the satisfaction with such a vehicle and might be a promising strategy for promoting BEVs.
Keep Your Scanners Peeled Hergeth, Sebastian; Lorenz, Lutz; Vilimek, Roman ...
Human factors,
05/2016, Letnik:
58, Številka:
3
Journal Article
Recenzirano
Objective:
The feasibility of measuring drivers’ automation trust via gaze behavior during highly automated driving was assessed with eye tracking and validated with self-reported automation trust in ...a driving simulator study.
Background:
Earlier research from other domains indicates that drivers’ automation trust might be inferred from gaze behavior, such as monitoring frequency.
Method:
The gaze behavior and self-reported automation trust of 35 participants attending to a visually demanding non-driving-related task (NDRT) during highly automated driving was evaluated. The relationship between dispositional, situational, and learned automation trust with gaze behavior was compared.
Results:
Overall, there was a consistent relationship between drivers’ automation trust and gaze behavior. Participants reporting higher automation trust tended to monitor the automation less frequently. Further analyses revealed that higher automation trust was associated with lower monitoring frequency of the automation during NDRTs, and an increase in trust over the experimental session was connected with a decrease in monitoring frequency.
Conclusion:
We suggest that (a) the current results indicate a negative relationship between drivers’ self-reported automation trust and monitoring frequency, (b) gaze behavior provides a more direct measure of automation trust than other behavioral measures, and (c) with further refinement, drivers’ automation trust during highly automated driving might be inferred from gaze behavior.
Application:
Potential applications of this research include the estimation of drivers’ automation trust and reliance during highly automated driving.
► Drivers experience range as sufficient after 3months of electric vehicle use. ► Users reserve substantial range safety buffers. ► Personality traits and system competence play a role in range ...utilization.
Limited driving range is an obstacle to adoption of electric vehicles (EVs). We examine from a self-regulation perspective the psychological dynamics underlying individual reference values for three different types of range constructs. In a 6-month field trial 40 EVs were leased to a sample of early adopter customers. In general, users were satisfied with range and stressful range situations rarely occurred. Results further suggested that users were comfortable with utilizing approximately 75–80% of their available range resources. Several personality traits (e.g., control beliefs, low impulsivity) and system competence variables (e.g., daily practice, subjective competence) were positively related to range level values and thus range utilization. Comfortable range was positively related to range satisfaction. We recommend that psychology-based strategies should be applied to enhance range optimization.
•Younger and older drivers consider driving automation trustworthy and acceptable.•The initial system experience significantly increases trust and acceptance.•After the initial system experience, ...trust and acceptance remain on a stable level.•Especially older drivers show a positive attitude towards driving highly automated.•Age-specific acceptance barriers regarding automotive technologies are identified.
Highly automated driving (HAD) is expected to improve future road transport, especially for older adults, provided that it is trusted and accepted by drivers. Research on Advanced Driver Assistance Systems (ADAS) suggests that system experience can enhance drivers’ trust and acceptance. To evaluate the transferability of this result to HAD, we examined the development of drivers’ trust and acceptance regarding this technology at different stages of system experience in a driving simulator as well as on a test track. Age effects were additionally addressed by comparing the results of 20 younger (25–45 years) and 20 older (65–85 years) drivers in the driving simulator study. Trust and acceptance were assessed before the initial system experience as well as after the first and second automated drive. Both age groups showed slightly positive a priori trust and acceptance ratings, which significantly increased after the initial experience and remained stable afterwards. Older drivers reported a more positive attitude towards using HAD despite their lower self-assessed self-efficacy and environmental conditions facilitating HAD-usage (e.g. technical support) compared to younger drivers. In the subsequent test track study, trust and acceptance of the younger driver group were assessed before and after experiencing HAD in a test vehicle. Neither trust nor acceptance decreased despite the absence of further system experiences between both studies and the increased realism on the test track. These results underline the importance of the initial system experience for HAD-trust and –acceptance and emphasize the significance of automotive technologies for the preservation of older drivers’ mobility.
