Some readers have asked about the source of the research upon which I base my contention that hands-free cell phones are no safer than hand-held. Here's one report:
This report in Psychology Matters cites different, newer studies from a variety of sources which essentially come to similar conclusions, although one study differentiates conversations by their 'complexity' - simple calls won't cause the same degree of distraction as more complicated ones, which makes some intuitive sense.
One study mentioned here also delivers the first evidence I've seen so far which does in fact assert that conversations with in-car passengers also cause driver distraction of a dangerous degree.
Now, to show you that we are as always balanced and fair, there is a website that claims hands-free IS in fact safer than hand-held. My reading of their report makes me believe that their conclusions are not based on actual research data, but on their assumptions about what goes on in a car. They also quote a CNN TV report as as source. Hmm-mm - I think I'll stick with Drs. Redelmeier and Tibshirani.