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Effects of manual versus voice-activated dialing during simulated driving.

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Jenness JW, Lattanzio RJ, O'Toole M, Taylor N, Pax C. · 2002

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Voice-activated phone dialing reduces driving errors by 22% and dangerous glances away from the road by 56% compared to manual dialing.

Plain English Summary

Summary written for general audiences

Researchers studied how using a cell phone while driving affects performance by comparing manual dialing versus voice-activated dialing in a driving simulator with 24 volunteers. They found that voice-activated dialing resulted in 22% fewer lane-keeping errors and 56% fewer glances away from the road compared to manual dialing. This suggests that while both methods of phone use impair driving, hands-free options create significantly less distraction than physically manipulating the device.

Why This Matters

This study reveals a crucial distinction that's often overlooked in discussions about cell phone safety while driving. The science demonstrates that the physical act of handling your phone creates measurably more cognitive disruption than voice commands alone. What this means for you is that the type of phone interaction matters significantly for your safety and that of others on the road. The reality is that both manual and voice-activated dialing still caused drivers to slow down compared to no phone use, indicating that any phone interaction creates some level of cognitive load. However, the 56% reduction in eyes-off-road time with voice activation represents a substantial safety improvement that could translate to real-world accident prevention.

Exposure Information

Specific exposure levels were not quantified in this study.

Study Details

The aim of this study is to invesitgate Effects of manual versus voice-activated dialing during simulated driving.

We measured driving performance (lane-keeping errors, driving times, and glances away from the road ...

There were 22% fewer lane-keeping errors (p<.01) and 56% fewer glances away from the road scene (p<....

Cite This Study
Jenness JW, Lattanzio RJ, O'Toole M, Taylor N, Pax C. (2002). Effects of manual versus voice-activated dialing during simulated driving. Percept Mot Skills 94(2):363-379, 2002.
Show BibTeX
@article{jw_2002_effects_of_manual_versus_2238,
  author = {Jenness JW and Lattanzio RJ and O'Toole M and Taylor N and Pax C.},
  title = {Effects of manual versus voice-activated dialing during simulated driving.},
  year = {2002},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/12027325/},
}
PubMed: 12027325

Cited By (40 papers)

Quick Questions About This Study

Yes, hands-free calling significantly reduces driving impairment compared to manual dialing. A 2002 driving simulator study found voice-activated dialing caused 22% fewer lane-keeping errors and 56% fewer glances away from the road than manual dialing, though both methods still impaired driving performance.
Voice dialing is considerably safer than manual dialing while driving. Research shows drivers made 22% fewer lane-keeping errors and looked away from the road 56% less when using voice-activated dialing compared to manually dialing their phone during simulated driving tasks.
Yes, cell phone use while driving increases lane departure errors. A controlled study found that both manual and voice-activated dialing caused significantly more lane-keeping errors compared to no phone use, with manual dialing creating the most severe impairment.
Manual phone dialing substantially impairs driving performance by increasing lane-keeping errors and visual distraction. Research shows manual dialing causes 22% more lane errors and 56% more glances away from the road compared to hands-free voice dialing options.
Yes, drivers appear to compensate for phone-related distractions by reducing their driving speed. A 2002 study found significantly longer driving times during both manual and voice-activated dialing conditions, suggesting drivers instinctively slow down when using phones while driving.