Visual and cognitive demands of using Apple's CarPlay, Google's Android Auto and five different OEM infotainment systems

Strayer, DL; Cooper, JM; McCarty, MM; Getty, DJ; Wheatley, CL; Motzkus, CJ · 2018 · publications_jsonl

archive: archived pipeline: cataloged verified

Get this paper ↗ (search — opens at the source; we link to it, we don't host it)

Summary

This study investigates the cognitive workload imposed on drivers by voice-based interactions with three intelligent personal assistants: Apple’s Siri, Google’s Google Now, and Microsoft’s Cortana. Motivated by the growing prevalence of smartphone integration in vehicles and the need to evaluate auditory/vocal interfaces for safety guidelines, the research aims to determine whether these systems impose cognitive demands comparable to single-task driving or high-load mental tasks. The study also seeks to identify if older drivers experience greater dual-task costs than younger drivers and to compare the performance of these smartphone systems against previously tested embedded vehicle systems. The researchers conducted two on-road experiments using an instrumented vehicle on a 2.7-mile suburban course in Salt Lake City. Thirty-one participants, aged 21 to 70, drove while performing secondary tasks such as dialing numbers, calling contacts, and selecting music via the three smartphone systems. Cognitive workload was measured using a Detection Response Task (DRT) device worn by participants, which recorded reaction times and hit rates to peripheral visual stimuli. Primary task performance was assessed via video analysis of driving speed and system errors, while subjective workload was measured using the NASA TLX survey. The study utilized a within-subjects design comparing single-task driving, the three smartphone assistants, and a high-workload Operation Span (OSPAN) task. Results indicated that cognitive workload was significantly higher during smartphone interactions than during single-task driving. Google’s system placed significantly lower cognitive demands on drivers than Apple’s Siri and Microsoft’s Cortana, which did not differ from each other. This difference was associated with fewer system errors, shorter task completion times, and higher ratings of intuitiveness for the Google system. Surprisingly, the "on-task" workload measures for interacting with the devices were comparable to the high-demand OSPAN task, suggesting severe cognitive distraction. Additionally, the study found residual cognitive costs that persisted after the interaction ended, taking significant time to dissipate. No significant differences in workload were found between age groups, indicating that older drivers did not exhibit greater dual-task costs than younger drivers in this context. The findings imply that voice-based smartphone technology poses substantial risks to driving safety due to high cognitive workload, despite allowing drivers to keep their eyes on the road. The equivalence of smartphone interaction workload to a mentally demanding OSPAN task suggests that these interactions are incompatible with safe driving. The study highlights that system design features, such as error rates and intuitiveness, significantly impact driver workload. These results support caution in the use of smartphone voice-based technology in vehicles and provide empirical data for developing voluntary guidelines to minimize driver distraction. The research underscores the importance of evaluating not just visual-manual interference but also cognitive demands when assessing in-vehicle technologies.

Key finding

Voice-based interactions with in-vehicle information systems impose moderate to high cognitive workload that is significantly higher for older drivers and persists as residual impairment for up to 27 seconds after the task concludes, unaffected by five days of practice.

Methodology

on_road

Sample size: 257

Provenance

The full processing record for this entry. Every stage of this paper's journey through the pipeline is logged — what ran, with which tool and model, how many attempts it took, and when it last completed. Discovered via qwen3.6_summarize on 2026-05-29 (4 acquisition events logged).

Summary generated by qwen3.6-27b-prismaquant on 2026-06-10; verification: verified.

Topics

Ranked by relevance to this paper. Hover a topic for its definition.

• mental demand
• infotainment
• temporal
• visual manual
• voice interaction
• auditory

Information type

What kind of knowledge this paper contributes, grouped by family — independent of topic (what it is about) and method (how it was studied).

• Applied Guidance: design guidelines
• Empirical Findings: behavioral performance data
• Methodological Resource: tool software