Levels of driving automation from a user’s perspective: How are the levels represented in the user’s mental model?

Abstract

In this explorative study, we focused on the number of levels of driving automation as part of the mental model, using a newly created online questionnaire and analyzing results using Principal Component Analysis. The online questionnaire consisted of 20 automated driving functions that were described in short sentences. The 247 participants subjectively rated the degree of automation of the 20 functions on a 7-point rating scale. Using Principal Component Analysis, the ratings were summarized into groups represented by the components based on correlative relationships. The results yielded three components, which can be interpreted as three levels of driving automation. These three levels differ from the well-established taxonomies, showing that users do not differentiate between five or six levels of driving automation.