Human-Machine interfaces and vehicle Automation: A review of the literature and recommendations for system Design, Feedback, and alerts

The effectiveness of the human–machine interface (HMI) in a driving automation system is based, in part, on how it issues alerts and requests to the driver—it must quickly and sufficiently orient the driver to the driving task. While much research on the design of HMIs exists, unique associations and meaningful relationships must be considered collectively to offer guidance for vehicle automation. The purpose of the current study was to: (a) review and synthesize existing research and guidance on HMI design as it related to requests to intervene (RTI) for driving automation systems and (b) propose a clear and comprehensive set of recommendations that could inform future system development and implementation. A thorough literature search and selection process was followed the PRISMA guidelines and resulted in the review of 93 articles. The review’s outcome indicates multimodal alerts are prominent, useful, and effective. Many of the HMIs reported in the literature were similar in that they abided by well-established HMI-design guidelines. A small subset of HMIs established evidence for distinct and innovative design principles. Taken together, this study proposed 10 recommendations for HMI design in driving automation systems, ranging from the utility of auditory versus visual alerts to the timing, sensitivity, and location of alerts.