Conceptual design and evaluation of a human machine interface for highly automated truck driving

Vehicle automation is linked to various benefits such as an increase in fuel and transport efficiency, as well as an increase in driving comfort. Automation also comes with a variety of downsides e.g. loss of situation awareness, loss of skills as well as inappropriate trust levels regarding system functionality. Drawbacks differ between automation levels. As highly-automated driving (level 3) requires the driver to take over the driving task in critical situations within a limited period of time, the need for an appropriate human-machine interface (HMI) arises. To foster adequate and efficient humanmachine interaction, this contribution presents a user-centered, iterative approach for HMI design for highly-automated truck driving.An expert workshop was conducted to develop first ideas and HMI ketches. Workshop results were combined with scientific findings regarding HMI design for highly-automated car driving. Based on those findings, a paper prototype was created and evaluated with experts, using an approach of mixed qualitative methods (heuristic evaluation, thinking aloud). The outcome was implemented to the HMI concept. In a third step, the HMI was conceptualized as video prototype enabling a more detailed evaluation. Again, experts were asked to assess the HMI using qualitative (thinking aloud) and quantitative methods (questionnaires).The result represents a video prototype showing a HMI strategy for highly-automated driving, aiming at fostering a successful human-machine interaction. Relevant issues such as drivers' informational needs, situation awareness and trust were explicitly considered during HMI design. Next steps comprise HMI implementation and user evaluation in a driving simulator to let users experience the HMI in a semi-real driving context.