Micromobility vehicles (MMVs) – lightweight vehicles such as bicycles, e-bikes, and (e-)scooters have emerged as an increasingly prominent urban transportation mode, and are expected to constitute a substantial part of future traffic systems. However, their growing presence introduces safety concerns to both MMV riders and surrounding road users (RUs), as MMV interactions often exhibit uncertainty regarding their behavior or intent. Among them, e-scooters – as a relatively new type of MMV – pose particularly significant challenges due to their maneuver flexibility, variable rider behaviors, limited signaling measures, and frequent space sharing, while unfamiliarity with them exacerbates these challenges. While existing measures primarily focus on infrastructure design, regulatory enforcement, and behavioral education, little attention has been given to vehicle-based solutions.

This thesis presents a Research-through-Design project that explores how vehicle embodiment, including physical form and dynamic elements, can support the intent legibility of an e-scooter during traffic interactions. The objective is to develop an e-scooter design with functions and features that enable interacting RUs to perceive the rider’s intent more accurately and promptly, therefore improving both objective and perceived safety in mixed urban traffic.

A literature review and interaction analysis identified critical intents in key interaction scenarios, and precedent research provided a theoretical basis and design inspiration, which informed the subsequent iterative design exploration. The final outcome is a proposed e-scooter design with enhanced intent legibility through its static form and dynamic lighting. Vehicle-based features and two form variations created by light and shadow effects improve predictability by aligning general expectations with the vehicle’s behavioral characteristics, which serves as an implicit communication layer. Explicit light signals adopt both conventional signals and newly designed priority signals building on perceptual associations. Together, the light elements improve the vehicle’s detectability and directionality, also providing explicit intent communication in relevant scenarios.

A user study evaluated the form transformation and explicit priority signals. The results suggested that the form transformation successfully influenced behavioral expectations in the intended direction regarding the likelihood of traveling at a high speed, exhibiting greater maneuverability, and claiming priority during interactions. However, it did not bias intent interpretation in unsignalized crossing encounters. The yielding signal demonstrated potential in supporting yielding intent perception, while the proceeding signal produced inconsistent interpretations. The findings indicated that further refinement should prioritize existing traffic-related associations, and establish stronger and more distinguishable semantic associations. In general, there is an increase in the ease of interpretation ratings with the presence of explicit signals, suggesting that they can potentially facilitate intent interpretation by improving the salience of communicative cues.

The proposed design demonstrates its technical feasibility to be realized as a next-generation mobility product, although further ergonomics research, engineering development and valida-tion are required before implementation.

Beyond the proposed design itself, the project demonstrates a systematic approach to enhance intent expression through vehicle embodiment. The resulting communication strategy and findings can inform design and research for future e-scooter development, offer transferable insights for other MMVs and the broader mobility field on improving intent communication in mixed traffic environments. ... Read more