Background
Automated driving will be of high value in the future. While in partial-automated driving the driver must always monitor the traffic situation, a paradigm shift is taking place in the case ...of conditional automated driving (Level 3 according to SAE). From this level of automation onwards, the vehicle user is released from permanent vehicle control and environmental monitoring and is allowed to engage in Non-Driving Related Tasks (NDRT) in his or her newly gained spare time. These tasks can be performed until a take-over request informs the user to resume vehicle control. As the driver is still considered to be the fall-back level, this aspect of taking over control is considered especially critical.
Methods
While previous research projects have focused their studies on the factors influencing the take-over request, this paper focuses on the effects of NDRT on the user of the vehicle during conditional automated driving, especially on the human workload. NDRT (such as Reading, Listening, Watching a movie, Texting and Monitoring ride) were examined within a static driving simulator at the Institute of Ergonomics & Human Factors with 56 participants in an urban environment. These NDRT were tested for mental workload and the ability to take over in a critical situation. To determine the perceived workload, the subjective workload, psychophysiological activity as well as performance-based parameters of a secondary competing task performed by a were used.
Results
This study revealed that the selected NDRT vary significantly in their mental workload and that the workload correlates with the length of the time needed for take over control. NDRT which are associated with a high workload (such as Reading or Texting) also lead to longer reaction times.
•This study elucidated the influence of privacy on the usage of connected vehicles.•The setting took place in a high-fidelity driving simulator.•Results revealed that privacy-related factors shape ...acceptance of connected services.•The structure of the validated model resembles the structure of the privacy calculus.
Modern cars are becoming increasingly connected. While connectivity enhances the car’s functional portfolio, it fosters the relevance of information privacy in the private vehicle. This research paper sets out to elucidate the role of data disclosure in the acceptance of connected services in the car. Based on Davis’ Technology Acceptance Model, we postulate an acceptance model which accounts for informational privacy in the connected car. In a high-fidelity driving simulator study, 116 participants interacted with a connected parking service and subsequently responded to an acceptance questionnaire. Structural equation modelling revealed a significant influence of privacy-related factors on attitude towards using the system, which in turn directly influences usage intention. The results underscore the relevance of informational privacy for the acceptance of connected vehicular services.
Background
Driving fatigue can have serious consequences. Too often fatal accidents are caused by fatigue. However, it is not uncommon for fatigue to occur while driving when the driver is ...under-challenged. Due to the increasing automation of vehicles, it is foreseeable that the number of accidents caused by monotony will increase. Interactions between driver and vehicle through gamification can remedy the situation and provide the driver with new stimuli during an otherwise monotonous journey.
Methods
In order to test the effectiveness of such interactions, we conducted a driving simulator study with 31 test persons to investigate driving performance and psycho-physiological parameters. Each subject ran through the experiment three times in randomized order to test the interaction system in comparison to a ride in which the driver was alone and a ride in which the driver had a co-driver.
Results
The results provide clear indications of safer driving of the test subjects when driving with gamification and with a passenger. The tested interaction system prevents upcoming fatigue in a similar way to communication with a passenger. The experiments also provide insights into the effects of monotony in vehicle driving.
Zusammenfassung
Hochautomatisierte Fahrzeuge werden in der Lage sein, die Fahrzeugführung selbständig zu übernehmen, während sich die Fahrer_innen mit fahrfremden Tätigkeiten beschäftigen können. In ...kritischen Situationen, die das Automatisierungssystem nicht allein bewältigen kann, wird es jedoch weiterhin Übernahmeaufforderungen an den Fahrer/die Fahrerin geben. In diesem Beitrag wird untersucht, welche Modalitäten für Übernahmeaufforderungen entsprechend einer Reiz-Reaktions-Kompatibilität geeignet sind. Dazu wurden drei unterschiedliche Schnittstellen-Varianten entwickelt und mit insgesamt 126 Proband_innen in zwei unabhängigen Fahrsimulator-Studien überprüft. Innerhalb der ersten Studie wurden eine visuelle, eine vibrotaktile oder eine multimodale (Kombination aus visueller, vibrotaktiler und akustischer) Übernahmeaufforderung untersucht. Die zweite Studie konzentrierte sich auf die mentale Beanspruchung und die Rückübernahmefähigkeit bei Ausführung verschiedener fahrfremder Tätigkeiten während hochautomatisierter Fahrt. Diese Studie ergab, dass die Dauer der Kontrollübernahme nach einer multimodalen Rückübernahmeaufforderung mit der mentalen Beanspruchung der fahrfremden Tätigkeiten korreliert.
Praktische Relevanz
: Die Untersuchung unterschiedlicher Modalitäten für die Informationsübermittlung bei einer Rückübernahmeaufforderung trägt dazu bei, dass in automatisierten Fahrzeugen Modalitäten gewählt werden, die zum einen eine kurze Reaktionszeit der Fahrer_innen unterstützen und zum anderen eine subjektiv positive Bewertung hervorrufen.
•Subjects initiated braking significant earlier in the field than in driving simulator.•Subjects in driving simulator showed significantly higher speed and braked distinctly more intensively than in ...the field.•In driving simulator, the subjects appeared to have reduced risk awareness.•Caution is required when using a driving simulator for designing intersection assistance systems.
Introduction: The majority of accidents involving personal injury occur in urban intersections. As human error is the primary cause of these accidents, it seems reasonable to support drivers by intersection assistants. Studies to evaluate such systems are usually performed in driving simulators. However, this implies driver behaviour validity, which cannot always be taken for granted due to the artificial nature of simulated environments. The paper pays special attention to the validity of braking behaviour in urban intersections. In particular, the effect of the test scenario and selected driving simulator design parameters is considered. Method: The Time to Intersection (TTI) time interval between field and simulator study was evaluated at five simple urban intersections. Results: Independently of the type of intersection and the parameter configuration of the simulator, subjects initiated braking in preparation for a turning manoeuvre significantly earlier in the field than in the driving simulator. In particular, the results of both tests differed more at intersections where the driver did not have right of way than at intersections with other layouts, confirming the impact of the test scenario. Some differences were also found when the driving simulator parameter set was varied. Conclusions: The braking behaviour near urban intersections differs between real and simulated experimental environments. From these results, we conclude that caution is required when designing intersection assistance systems based solely on the braking behaviour of subjects in simulated environments. The test scenario and the design parameters must be considered as factors which influence the results. Practical applications: Depending on the current traffic situation and interactions, multiple different kinds of accident can occur at the considered types of intersection, meaning that closely investigating the driver behaviour validity at these junctions is highly important for further intersection assistance systems. Validity of TTI is for example important when determining the best choice of warning interval for a turning assistance system.
The aim of this study is to identify suitable science-based methods for measuring monotony-related fatigue. Monotony is one of three causes of fatigue that to date has rarely been considered in ...isolation. With an ongoing automation of the driving task the drivers monotony will drastically increase in the future. The methods used, such as the questions asked in interviews, can influence and distort the monotony experienced by subjects during driving tests. For this reason, not all measurement methods generally used to measure fatigue can be used when studying the role of monotony. A systematic literature search based on previously defined criteria allowed us to identify 53 publications which adequately described and evaluated the measurement methodology used to measure fatigue. The result was a list of 25 methods used in the 53 studies that we analysed. These include studies of drivers' condition data and data about their performance. The measurement methods were evaluated based on the evaluations published by the authors who used each method. Further the methods influence on a monotonous study design was critically discussed by the authors of this paper. The paper concludes with a derived measurement concept for simulated driving tests. This work supports future research teams in the selection of a suitable measurement concept for investigating monotony related fatigue and appropriate countermeasures.
Zusammenfassung
Bereits heute wird die Kommunikation zwischen automatisierten Fahrzeugen und anderen Straßenverkehrsteilnehmenden entwickelt und erforscht, um zukünftig einen sicheren und effizienten ...Straßenverkehrsfluss zu gewährleisten. Dieser Beitrag zielt darauf ab, Gestaltungsdimensionen der Kommunikation zwischen automatisierten Fahrzeugen und anderen Straßenverkehrsteilnehmenden herzuleiten und zu analysieren. Folgende Fragestellung steht im Vordergrund: Wie kann eine Kommunikationsstrategie zwischen automatisierten Fahrzeugen und anderen Straßenverkehrsteilnehmenden gestaltet werden? Zur Beantwortung dieser Fragestellung werden Gestaltungsdimensionen theoretisch abgeleitet und eine Befragung (
N
= 30) und Beobachtung (
N
= 308) von Fußgänger/-innen in Testfeldern von automatisierten Bussen durchgeführt. Aufbauend auf Erkenntnissen der Kommunikationstheorie werden sechs Gestaltungsdimensionen (Wer, Warum, In welcher Situation, Was, Wann, Wie) und dahinterstehende zentrale Fragestellungen identifiziert. Die Ergebnisse der empirischen Studien zeigen Verhaltensweisen und den Kommunikationsbedarf von Fußgänger/-innen bei der Interaktion mit automatisierten Bussen. Die Analyse anhand der Gestaltungsdimensionen legt weiteren Forschungsbedarf offen, wie z. B. nach den zukünftigen Rollen aller Beteiligten im Straßenverkehr.
Praktische Relevanz
Die Anwendung des Frameworks von Gestaltungsdimensionen unterstützt bei der Gestaltung der Kommunikation von automatisierten Fahrzeugen, um zukünftig die notwendige Kooperation zwischen Straßenverkehrsteilnehmenden sicherzustellen.
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