Comic layouts are increasingly shaped by the interaction affordances of reading devices, such as scrollable smartphone comics. eXtended Reality (XR) headsets are emerging media consumption devices, offering spatial affordances for new comic layouts. We investigated how XR could enhance comic experiences through participatory design with comic creators, readers, and HCI experts. Participants used ComiXR, our novel XR comic platform, to adapt a print comic for XR while thinking aloud. Participants preferred spatially placed panels that use depth to separate characters from backgrounds. Ambient sound and haptics enhanced immersion, while eye-tracking addressed limitations, e.g. hiding spoilers. However, comic creators expressed potential difficulty in authoring these non-visual elements. Participants explained that XR comic layouts could change between stationary and public mobile settings, where social acceptability and situational awareness become prominent challenges. Our findings support the continued cultural and artistic significance of comics and identify new use cases for XR.

Automated vehicles (AVs) must communicate their yielding intentions to pedestrians at crossings. External Human-Machine Interfaces (eHMIs, on-vehicle displays) are promising solutions, but were primarily tested with walking pedestrians. Runners are a significant pedestrian group who move faster and face distinct bodily and perceptual demands, raising questions about how pedestrian activity influences eHMI use. We conducted an outdoor study using an augmented reality simulator. Participants navigated a virtual crossing while walking and running; an approaching AV displayed one of three eHMIs: red/green colour-changing lights, animated cyan lights, or no-eHMI. No-eHMI consistently underperformed. Walkers mostly stopped and validated eHMI signals with vehicle behaviour; they processed both eHMI animations and colour changes effectively. Runners experienced greater time pressure to cross, increasing reliance on the eHMI over vehicle behaviour. They preferred colour changes over animation for rapid decisions. These findings are crucial for promoting eHMI inclusivity and physical wellbeing as AVs join our roads.

Cyclists need interfaces such as on-vehicle displays or augmented-reality (AR) glasses for effective communication with autonomous vehicles (AVs) when human drivers are no longer present. Interfaces must handle complex situations involving multiple AVs around a cyclist. Holistic AV-Cyclist Interfaces (HACIs) are a novel solution; they group interfaces into a multimodal interconnected system to support the rider. However, the best way to present information is uncertain. We explored this in a scenario with three AVs using CycleARcade, a new multi-user AR platform for designing and evaluating HACIs. Cyclists and HCI researchers collaboratively created and tested HACIs within CycleARcade through a novel iterative participatory design method. We synthesised three HACIs from this process and assessed them with riders in CycleARcade. Participants preferred HACIs with AR displays integrated into the environment to avoid road distractions, paired with spatial audio communicating AV proximity. These findings provide crucial input for the real-world deployment of AVs.

Cultural differences influence how cyclists and drivers interact, affecting global autonomous vehicle (AV) adoption. AV-cyclist interfaces are needed to clarify AV intentions and resolve ambiguities when no human driver is present. These must adapt across cultures and road infrastructure. We conducted the first cross-cultural AV-cyclist user study across Stockholm (high segregation of cyclists from drivers), Glasgow (some segregation), and Muscat (no segregation). Cyclists used an AR simulator to cycle in physical space and experienced three holistic AV-cyclist interfaces. These integrated multiple interfaces into a larger ecosystem, e.g., a smartwatch synchronised with on-vehicle eHMI. Interfaces communicated AV location, intentions, or both. Riders from all cities preferred combined AV location and intention information but used it differently. Stockholm cyclists focused on location, validating intentions with driving behaviour. Glasgow riders valued both cues equally. Muscat cyclists trusted interfaces, prioritising intentions without relying on driving behaviour. These insights are key for global AV adoption.

AV-cyclist interaction research has focused on individual interfaces, e.g., eHMIs or AR glasses. However, cyclists using multiple independent interfaces could receive redundant or contradictory messages, causing unsafe encounters. We introduce the Holistic AV-Cyclist Interface: multiple displays facilitating communication together to ensure safe road sharing. We used participatory design with cyclists and HCI researchers (N = 12) to develop holistic interfaces around an actual vehicle equipped with an eHMI. Participants created holistic interfaces communicating blindspot warnings and AV intent and accommodating two-way communication, e.g. through on-bike directional indicators. They mostly placed interfaces on the bicycle handlebars and cycling accessories, e.g. helmet. Holistic interfaces could overcome design challenges: they can be multimodal, facilitate communication between AVs and multiple cyclists, and work in varying weather/visibility conditions. We categorised participant designs into a taxonomy and developed a novel holistic interface based on our findings. Our results are important for the safe integration of AVs into traffic.

The social cues drivers exchange with cyclists to negotiate space-sharing will disappear as autonomous vehicles (AVs) join our roads, leading to safety concerns. External Human-Machine Interfaces (eHMIs) on vehicles can replace driver social signals, but how these should be designed to communicate with cyclists is unknown. We evaluated three eHMIs across multiple traffic scenarios in two stages. First, we compared eHMI versatility, acceptability and usability in a VR cycling simulator. Cyclists preferred colour-coded signals communicating AV intent, easily seen through quick glances. Second, we refined the interfaces based on our findings and compared them outdoors. Participants cycled around a moving car with real eHMIs. They preferred eHMIs using large surfaces on the vehicle and animations reinforcing colour changes. We conclude with novel design guidelines for versatile eHMIs based on first-hand interaction feedback. Our findings establish the factors that enable AVs to operate safely around cyclists across different traffic scenarios.

Autonomous vehicles (AVs) must communicate their intentions to nearby road users and may use external Human-Machine Interfaces (eHMIs). Most eHMIs have focused on interaction with pedestrians at crossings. However, these may not work for cyclists, who can be anywhere around vehicles and encounter them in diverse traffic scenarios. We used participatory design with cyclists and AutoUI researchers (N = 12) collaborating in a real-world setting to design eHMIs around an actual vehicle. Participants preferred eHMIs that co-exist with traditional vehicle signals and use a single design language across traffic scenarios to communicate awareness and intent quickly without distracting their attention from the road. We used our findings to develop a taxonomy of eHMI features for cyclists, allowing us to synthesise the designs and contribute versatile eHMI concepts catered to cyclists’ needs. This is important to ensure AVs can safely navigate and interact with cyclists in all road scenarios.

Cyclists encounter drivers in many traffic scenarios; good communication is key to avoiding collisions. Little is known about everyday driver-cyclist interaction and communication. This is important in designing Automated Vehicles (AVs) that must drive safely around cyclists. We explored driver-cyclist interaction across diverse scenarios through in-the-wild observations (N = 414) and a naturalistic study involving cyclists wearing eye-trackers (N = 12). Results showed cyclists attended to road markings and traffic signs in controlled traffic scenarios but to vehicle sides and windows in uncontrolled encounters. Interactions were unlikely at controlled intersections, but various techniques were used to negotiate right-of-way in uncontrolled scenarios, e.g. cyclists used arm gestures and shoulder checks to communicate their intent and awareness when lane merging. Drivers communicated these through on-vehicle signals and head movements at roundabouts. We discuss the implications of driver-cyclist interaction behaviour on AV interaction design and offer insights into system requirements to support cyclists riding in traffic.

Research on cyclists‘ safety and comfort is a growing topic. Existing works address support systems with novel interaction concepts such as augmented reality but also the design and evaluation of high-fidelity bicycle simulators. Since the field is still in its exploratory phase, there have been few attempts to systematically provide guidance for conducting experiments. For example, there is no consensus on the choice of representative driving scenarios, the proper choice of different bicycle simulators, and measurement standards to systematically compare the results of different studies. With this workshop, we want the community to gather and discuss a roadmap for the future of HCI bicycle research so that these issues can be overcome.