There was an insurance group study about 2-4 years back that looked at activities undertaken by drivers who were inattentive and had accidents. The study showed hands down it was radio play variants that occupied most of the top 10 activities. They separated things like radio, CD, etc. Food and drink were in there a couple of times as well. Makeup was in there as well. I remember the insurance industry leaders speak of food and radio being consistently high in the studies (it was on NPR). I don't see anyone leading the charge to eliminate radios from cars.

However, I don't necessarily think these things create driver inattentiveness rather than simply being the reason of the moment. Inattentive people will be that way regardless of how they do it. For about 2 years in an employer-provided van I had 6 accidents...all by people not looking over their shoulders when they wanted to change lanes...most in work traffic, a couple at night...WITH LIGHTS on dark roads!!! I see this several times a week still. Apparently you only have to look over your shoulder for the original driver's test...after that, don't bother. Anyway, it is hard to blame an activity when people make choices to engage in activities beyond their abilities. Hell, many people can't drive and TALK at the same time...especially you hand-talkers!