Evaluating the impact of phone interface modality on response times to stimuli in conventional and semi-automated vehicles

Abstract

This study investigates response times to stimuli within a driving environment in the presence of secondary non-driving tasks involving cell-phone usage by the driver. Two interaction modalities are employed for text reply while at the wheel: manual text replies and vocal text replies. The study evaluates the impact of the two modalities on throttle response time after a traffic light turns green (city scenario), as well as steering, braking, and throttle response times in a semi-automated vehicle that transitions from automated driving to manual conventional driving (highway scenario). Both scenarios were tested with the two investigated interfaces in a human-in-the-loop simulator. Moreover, the paper includes an analysis of time-to-reply to message, and analyzes different trends in texting behavior when the two interfaces are employed.