Cognitive load and detection thresholds in car following situations: safety implications for using mobile (cellular) telephones while driving.
Lamble D, Kauranen T, Laakso M, Summala H · 1999
View Original AbstractMobile phone conversations impair driving reaction times by 0.5 seconds regardless of whether phones are handheld or hands-free.
Plain English Summary
Researchers tested 19 drivers on a real highway to see how mobile phone use affects their ability to react when the car ahead brakes. They found that both hands-free phone conversations and manual dialing delayed drivers' brake reaction times by about 0.5 seconds and reduced their collision avoidance time by nearly 1 second. This demonstrates that hands-free phone options don't eliminate the safety risks of mobile phone use while driving.
Why This Matters
This 1999 study provides crucial evidence that the cognitive demands of mobile phone use, not just the physical handling of devices, create dangerous driving impairments. The researchers found that mental tasks like phone conversations produced reaction delays nearly identical to visual distractions like dialing numbers. What makes this research particularly significant is that it directly challenges the widespread belief that hands-free phone use is safe while driving. The reality is that your brain's capacity for attention is limited, and phone conversations compete with driving for these critical cognitive resources. At highway speeds, a half-second delay in braking can mean the difference between stopping safely and a rear-end collision.
Exposure Information
Specific exposure levels were not quantified in this study.
Study Details
This study was aimed at investigating drivers' ability to detect a car ahead decelerating, while doing mobile phone related tasks.
Nineteen participants aged between 20 and 29 years, (2000-125000 km driving experience) drove at 80 ...
The results indicated that drivers' detection ability was impaired by about 0.5 s in terms of brake ...
It was concluded that neither a hands-free option nor a voice controlled interface removes the safety problems associated with the use of mobile phones in a car.
Show BibTeX
@article{d_1999_cognitive_load_and_detection_2334,
author = {Lamble D and Kauranen T and Laakso M and Summala H},
title = {Cognitive load and detection thresholds in car following situations: safety implications for using mobile (cellular) telephones while driving.},
year = {1999},
url = {https://pubmed.ncbi.nlm.nih.gov/10487336/},
}