I would venture to say that those same people who are notorious for texting while driving are also just as likely to be putting on makeup, fiddling with the rad

I would venture to say that those same people who are notorious for texting while driving are also just as likely to be putting on makeup, fiddling with the radio, trying to eat a sandwich, or yelling at their kids. Thus, the net amount of bad driving due to cell phones may not be as large as previously expected.