Comparing Driver Distraction in Touchscreen and Physical Vehicle Interfaces
Samyukta Iyengar and Ross Bower
College of Computing & Informatics, Drexel University
Introduction
Over the past decade, in-car interface design has shifted dramatically from predominantly physical buttons and knobs to more screen-based and software-driven systems. Touchscreen dashboards and digital “infotainment” platforms now control a wide range of vehicle functions, from navigation and climate control to audio systems and safety features. While these interfaces offer flexibility, customizability, and visual interest, they also raise important questions regarding driver distraction. Unlike traditional physical controls, touchscreen systems often require sustained visual attention, precise touch targeting, and on-screen confirmations, all factors that may increase the amount of time drivers look away from the road.
Driver distraction remains a significant safety concern in transportation research and public policy. The U.S. National Highway Traffic Safety Administration (NHTSA) has established visual-manual distraction guidelines recommending that in-car tasks be designed such that single glances away from the roadway do not exceed two seconds and the cumulative glance time per task does not exceed 12 seconds. These thresholds provide an operational definition of “unsafe visual distraction,” and serve as a benchmark for evaluating vehicle interface safety.
Despite growing public debate and regulatory attention surrounding touchscreen-heavy vehicle designs, direct comparisons between physical control interfaces and touchscreen-based interfaces remain limited. Much of the existing literature focuses solely on optimizing touchscreen systems or evaluating specific touchscreen tasks, rather than systematically comparing interface types under standardized conditions. As a result, questions remain about how the type of vehicle interface may influence measurable distraction, and how drivers perceive safety and usability across different vehicle interfaces.
Conclusion
This study seeks to address this gap by empirically comparing two types of common in-car interfaces: a physical control-based system and a touchscreen-operated system. Using objective glance-based distraction metrics aligned with NHTSA guidelines, alongside task performance and subjective self-reporting, this research aims to evaluate whether certain vehicle interface types are associated with increased visual distraction while completing common driving-related tasks, with the goal of contributing empirical evidence to ongoing discussions about safer vehicle interface design. Ultimately, the findings of this study aim both to compare task performance and visual distraction across interface types and to inform design principles for reducing visual distraction in future vehicle systems.
While this study was limited by its participant count, the results were nonetheless clear. Compared to physical control participants, touchscreen participants averaged nearly 3x more glance deviations, accumulated more than 6x more eyes-off-road time, and produced 15x more NHTSA violations. Nearly half of touchscreen tasks exceeded the NHTSA's 12-second cumulative glance threshold while none of the physical control tasks did. Subjective ratings followed the same pattern — touchscreen participants reported lower usability, confidence and perceived safety. This was an exploratory pilot study with a small sample (n=4), so the findings have limited generalizability. However, this study demonstrates a sucessful technique for gathering distraction-related data without placing participants in harms way, opening the door for further research in this area.
This study examined the relationship between vehicle interface design and driver distraction by comparing touchscreen-based controls with traditional physical controls. Through a combination of objective performance metrics and subjective participant feedback, the results revealed clear differences between the two interface types. Across nearly all measured metrics, the touchscreen interface required greater visual attention, produced more frequent and longer glance deviations, and resulted in substantially higher cumulative “eyes-off-task” time compared to the physical control interface. These differences were also reflected in task performance outcomes, with touchscreen participants generally taking longer to complete tasks and experiencing more hesitation or correction during interaction.
Participants’ subjective perceptions closely aligned with these objective findings.
Participants using the touchscreen interface reported higher perceived visual demand, lower confidence when completing tasks while maintaining attention on the visual task, and lower perceived safety overall. In contrast, participants interacting with physical controls generally reported feeling more comfortable and required less visual attention to complete the same tasks. Together, these results support the study’s central hypothesis that tactile interaction through physical controls can reduce driver distraction during common in-vehicle tasks.
At the same time, the results also suggest that interface modality alone does not fully determine usability. Even within the physical interface condition, certain tasks produced moments of hesitation or confusion, indicating that control placement, labeling, and overall interface design remain important factors in minimizing distraction. Participant responses also highlighted a broader preference for hybrid interface systems that combine the tactile reliability of physical controls with the visual flexibility of digital displays.
Overall, these findings contribute to ongoing discussions about the safety and usability of touchscreen-dominant vehicle interiors. As automotive manufacturers continue to integrate increasingly complex infotainment systems into vehicle dashboards, understanding how interface design affects driver attention will remain an important area of study. Building on the results of this research, future work will explore how touchscreen interfaces might be redesigned to reduce visual demand and better support driver attention, with the goal of developing interface concepts that incorporate the advantages of both tactile and digital interaction.