Factors influencing the perception of safety in automated vehicles interiors
Authors: Fischer Lutz , Holder Daniel , Weiss Benedikt , Kiessling Jonathan , Reichelt Florian , Maier Thomas 
Published: April 2022

Significance and ObjectiveTechnological progress in the automation of passenger cars leads to numerous changes in driving functions, vehicle components and promises people higher individuality and safety. The driver becomes a passenger and the relief from the driving task allows the occupants to use and enjoy their travel time for secondary activities. The subjective driving experience, feeling of safety and the resulting trust are essential for the acceptance of automation . Whether people actually feel comfortable and safe in autonomous driving scenarios and which measures are best suited to improve trust in the automated system is the subject of current research. Therefore, product development strives for a holistic optimisation of the user experience. Based on the assumption that a positive user experience is achieved through the fulfilment of various basic needs [1], it is usually realised by both recording subjective needs and requirements for relevant use cases and the iterative adaptation of product features. Literature shows that the subjective perception of safety is one of these essential needs [2] and should be taken into account for optimising the user experience. This paper focuses on the subjectively perceived safety of occupants in automated vehicles. Within this contribution we provide an overview over factors influencing the need for safety based on both a broad literature review and an additional examination. Methods and ResultsIt is clear that a positive user experience is crucial for the success of automated driving. To investigate the subjective perception of safety in the vehicle, possible influencing factors were detected and structured based findings from literature [3, 4]. The identified factors can be clustered into “control”, “comfort of posture and operation”, “interior design”, “protective effect” , “safe driving experience”, “environmental factors” and “individual factors”. Each of these factors can be further subdivided, thus 26 sub-aspects related to subjective safety could be found. With this knowledge, a self-reflective questionnaire was created to determine the participants’ personal willingness to take risks and their perception of safety in vehicles. The focus was on the factors "environment" and "protective effect". The questionnaire was answered by N=101 participants in an online survey. An overwhelming majority of the participants confirmed safety as a very important factor for personal well-being in the vehicle. The overriding factors influencing subjective safety were rated individually by the respondents and prioritised in terms of their importance. It became clear that “control”, “safe driving experience” and “protective effect” are dominant factors. “Environmental factors” (except extreme conditions) and “interior design” play a subordinate role. In particular, "Full environmental coverage", "Tangible and visual safety features", "Driving style", "Traffic situation" and "Disaster potential" are important. Conclusion and OutlookThe participants were largely able to answer the questions targeting subjective safety. In particular, questions regarding "environmental factors" could be answered precisely in the online format. The differentiability in various aspects of the “protective effect” was not conclusively possible in the online format; therefore, we are going to conduct a comparative study in the driving simulator in the next step. References1.Hassenzahl, M., Diefenbach, S., Göritz, A.: Needs, affect, and interactive products – Facets of user experience. Interacting with Computers, vol. 22, 353–362 (2010). doi: 10.1016/j.intcom.2010.04.0022.Maslow, A.: A Theory of Human Motivation. Psychological Review, vol. 50, 370–396 (1943)3.Mandel, R.: Komfortmodell und Untersuchung zum Einfluss der Innenraumgeometrie auf die Wahrnehmung und Wirkung von Fahrzeugeigenschaften. Institut für Konstruktionstechnik und Technisches Design, Stuttgart (2019)4.Schnieder, E., Schnieder, L.: Verkehrssicherheit. Maße und Modelle, Methoden und Maßnahmen für den Straßen- und Schienenverkehr. Springer Vieweg, Berlin, Heidelberg (2013)