Driven to distraction

As Dr Christian Jarrett reports in The British Psychological Society’s Research Digest, using a hands-free phone whilst driving could be as dangerous as using a

Psychologists at the University of Illinois asked dozens of students to sit at the wheel of a driving simulator. Whilst driving they had to complete occasional second tasks that involved judging the accuracy of statements (speech comprehension) and repeated description (speech production). When performing either of these tasks, the students were less able to maintain a steady speed or distance behind another vehicle.

Researchers concluded that it is the "cognitive demands associated with communication, rather than the use of the phone itself, that interferes
with driving performance."