Automated vehicles are expected to improve traffic safety and efficiency. One approach to achieve this is via platooning, that is, (automated) vehicles can drive behind each other at very close proximity to reduce air resistance. However, this behavior could lead to difficulties in mixed traffic, for example, when manual drivers try to enter a highway. Therefore, we report the results of a within-subject Virtual Reality study (N=29) evaluating different platoon behaviors (single vs. multiple, i.e., four, gaps) and communication strategies (HUD, AR, attached displays). Results show that AR communication reduced mental workload, improved perceived safety, and a single big gap led to the safest merging behavior. Our work helps to incorporate novel behavior enabled by automation into general traffic better.
doi.org/10.1145/3613904.3642365
Introducing automated vehicles (AVs) on roads may challenge established norms as drivers of human-driven vehicles (HVs) interact with AVs. Our study explored drivers' decisions in game-theoretical scenarios amid mixed traffic using an online survey study. We manipulated factors including interaction types (HV-HV vs. HV-AV), scenario types (chicken game vs. public goods game), vehicle driving styles (aggressive vs. conservative), and time constraints (high vs. low). The quantitative results showed that human drivers tended to “defect” more, that is, not cooperate, against vehicles with conservative driving styles. The effect of vehicle driving styles was pronounced when interacting with AVs and in chicken game scenarios. Drivers exhibited more “defection” in public goods game scenarios and the effect of scenario types was weakened under high time constraints. Only drivers with moderate driving styles “defected” more in HV-AV interaction. Our qualitative findings provide essential insights into how drivers perceived conditions and formulated strategies for decision-making.
doi.org/10.1145/3613904.3642053
This paper reports results from a high-fidelity driving simulator study (N=215) about a head-up display (HUD) that conveys a conditional automated vehicle’s dynamic “uncertainty” about the current situation while fallback drivers watch entertaining videos. We compared (between-group) three design interventions: display (a bar visualisation of uncertainty close to the video), interruption (interrupting the video during uncertain situations), and combination (a combination of both), against a baseline (video-only). We visualised eye-tracking data to conduct a heatmap analysis of the four groups’ gaze behaviour over time. We found interruptions initiated a phase during which participants interleaved their attention between monitoring and entertainment. This improved monitoring behaviour was more pronounced in combination compared to interruption, suggesting pre-warning interruptions have positive effects. The same addition had negative effects without interruptions (comparing baseline & display). Intermittent interruptions may have safety benefits over placing additional peripheral displays without compromising usability.
doi.org/10.1145/3613904.3642219
To prevent motion sickness, Virtual Reality (VR) experiences for vehicle passengers typically present ``matched motion'': real vehicle movements are replicated 1:1 by movements in VR. To expand this design space, we provide foundations for in-car VR experiences that break free from this constraint by manipulating the passenger's visual perception of linear velocity through amplifying and reducing the virtual speed. In two on-the-road studies, we examined the application of Vehicular Translational Gain (1.5-9.5x) and Attenuation (0.66-0.14x) to real car speeds (~50km/h) across two VR tasks (reading and gaming), exploring journey perception, impact on motion sickness, travel experience and tasks. We found that vehicular gain/attenuation can be applied without significantly increasing motion sickness. Gain was more noticeable and affected perceived speed, distance, safety, relaxation and excitement, being well-suited to gaming, while attenuation was more suitable for productivity. Our work unlocks new ways that VR applications can safely enhance and alter the passenger experience through novel perceptual manipulations of vehicle velocity.
doi.org/10.1145/3613904.3642298
Walking is one of the greenest and most common travel modes. However, evidence shows a trend of decreased walking, and safety is a key barrier preventing many people from walking. Additionally, there is a limited understanding of pedestrians’ safe mobility practices and safety perception. Drawing on 449 survey responses from a representative sample in the United Kingdom, our work highlights how identities and walking situations intersect with individuals’ safety perceptions and diverse practices of pedestrians’ safe mobility. The role of technology used for negotiating safety and current challenges in both safe route planning and walking are also highlighted. Our work extends existing insights into pedestrians’ perception of safety and practices by adding empirical evidence and more nuanced contexts. This paper proposes two implications for design in response to design opportunities that surfaced from our mixed-method data analysis. Both the contributions and limitations of our work are also discussed.
doi.org/10.1145/3613904.3642896