# Interface Design for Responsible Remote Driving: A Study on Technological Mediation
## 4 Interface Design Analysis  
Compared to regular driving, controlling vehicles remotely through the mediation of HMIs transforms the perception of the road environment. These transformations impact on responsible driving in ways that are important to realize from a design perspective. While some perceptive limitations and hurdles are bound to emerge, in fact, opportunities to foster responsibility that are unavailable in the case of regular driving might also surface. To measure the extent of these transformations and their impacts on ROs' responsibility, it is crucial to understand how driving is mediated through HMIs, i.e., to clarify which aspects are amplified and which are reduced. This section zooms in on HMIs to evaluate the peculiar ways in which they mediate the RD experience. More specifically, it provides an analysis of opportunities and pitfalls with reference to RO's exercise of responsibility, which has not been a primary research focus so far. It does so in a preliminary way by discussing empirical evidence on RD HMIs presented in the literature through the methodological lenses of technological mediation. To better clarify how our research maps onto existing experimental research, a table of the empirical studies on which our analysis is based has been added to the present work as Appendix A. The results of this preliminary analysis, we hope, will contribute to inspiring future empirical research on responsible RD. Before starting the investigation, it is useful to introduce the main challenges that characterize RD HMI design in urban environments. As already noted, urban road environments are informationally complex, noisy, and chaotic. Promptly obtaining and maintaining SA is therefore a cognitively demanding but critical condition to safe and responsible RD--a condition that can only be satisfied through design. While the possibility of controlling vehicles is amplified through space, the associated possibility of accessing road environmental information is reduced and, thus, needs to be regained by means of HMI design. The technological mediation extending ROs' perception on to the road environment also presents its own amplifications and reductions. In this sense, the kinds and blends of information that HMIs mediate must be carefully balanced by design so to allow ROsto promptly process it without either lacking relevant pieces or being cognitively overwhelmed. RD HMI design, then, aims at striking the right balance to communicate the necessary information without overloading ROs' cognitive capabilities [4; 7]. Responsible RD, therefore, massively depends on the modes of its technological mediation. The analysis we propose aims at clarifying their significance and impact. Three macro-categories of informational feedback needed to obtain and maintain SA have been identified, corresponding to the human senses involved in the driving experience: sight, hearing, and touch. Accordingly, the investigation focuses on assessing how video, audio, and haptic feedback are conveyed. As Figure 2 schematically indicates, video feedback (Section 4.1) is mostly conveyed through monitors (Section 4.1.1) and sometimes enhanced with augmented reality features (Section 4.1.2), but innovative solutions such as head-mounted displays will also be considered (Section 4.1.3). Audio feedback (Section 4.2) is usually conveyed through headphones and microphones. Finally, HMIs for haptic feedback (Section 4.3) usually include steering wheels and pedals (Section 4.3.1), while research on seats, haptic displays, and wearables (Section 4.3.2) is still in its infancy. The following pages discuss the extent to which these interfaces contribute to making RD tasks less demanding, reducing workloads, enhancing safety, and putting ROs in the best conditions to exercise responsibility.