The More the Better? Comparison of Different On-board HMI Communication Strategies for Highly Automated Vehicles Using a LED Light-band to Inform Passengers about Safe Interactions with Multiple Surrounding Traffic Participants

Abstract

Highly automated vehicles (HAVs) are becoming more and more advanced and will be soon part of our traffic system. Although the drivers will no longer be in charge of the driving task, they remain an important part of the human-vehicle system and need to understand the HAV’s current and future behavior to feel safe and trust the vehicle automation. Research identified communication strategies using LED light-bands as a promising internal human-machine interface (iHMI) in the vehicle. Results show, that automation feedback regarding the detection of other traffic participants (TP) seems to be an important information for passengers to understand and anticipate vehicle behavior. However, these findings are limited to simple scenarios when the HAV interacted with only one other TP. Therefore, this current study investigates different communication strategies for more complex scenarios including a HAV interacting with multiple TPs simultaneously. In an online video study, 125 participants took over a HAV passenger’s perspective and rated different iHMI communication designs regarding the amount and arrangement of information and their perceived uncertainty regarding the HAV’s safe communication with surrounding TPs in a shared space scenario. Additionally, the maximum number of simultaneously presented TPs on the iHMI was investigated. Results revealed participants’ high information needs in complex situations with multiple TPs. Participants preferred iHMI designs displaying a maximum amount of information at a time. Prioritizing information led to enhanced subjective uncertainty. However, to avoid visual cluttering and displaying only relevant information on the iHMI, results needs to be critically discussed for future investigations.