Towards safe smartphone controls for cycling

Abstract

Recent developments in mobile phones, smartwatches, and peripherals (e.g., bicycle computers) have led to an increased use of mobile devices during various forms of physical activity. Whether by texting, navigating, playing music, or scrolling through information concerning their personal fitness, people interact with their devices while in motion. However, while smartphones and smartwatches have excellent sensing and processing capabilities, they may be difficult to interact with should users’ hands be occupied during physical activity. In this study, we design, implement, and evaluate two prototypes for smartphone control that do not require cycliststo remove their hands from the handlebars of their bicyles: The ROTATION device, which is a device that operates based on the rotation of a handlebar grip, and the BUTTON device, which is a handlebar-mounted device with three buttons. These devices are the result of a design process that included a preliminary study and the evaluation of a low-fidelity prototype and led to the identification of the key features required for an on-bicycle smart control. The devices were evaluated via a cycling experiment involving 19 participants who completed a series of common smartphone tasks. The study shows that handlebar-mounted smartphone controls can effectively reduce the cognitive load required to perform smartphone actions while cycling. This finding implies that using bicycle-specific controllers reduces the attention that cyclists have to devote to interacting with their devices and leaves them with more cognitive capacity for responding to traffic. In addition to reducing the cognitive load, the ROTATION device causes significantly fewer deviations from the intended path while cycling. In summary, this work contributes insights into designing safe interfaces for interacting with mobile devices while cycling.