The Effects of Mobile Phones and Hands-Free Laws on Traffic Fatalities

Using state-level panel data on mobile phone ownership, hands-free laws, and traffic fatalities, this paper finds that mobile phone ownership is associated with higher traffic fatalities, but only in bad weather or wet road conditions. The limited experience of a few states suggests that hands-free laws reduce traffic fatalities, but again only in bad weather or wet road conditions, and possibly also in rush-hour traffic. The findings suggest that the benefits of hands-free laws depend on driving conditions, and an important policy implication is hands-free laws should be more strongly enforced when driving conditions are more difficult. These findings on hands-free laws differ from other research, which consistently finds that hands-free and handheld phone usage have similar effects on driver distraction and accident risk, calling into question the usefulness of hands-free laws.