<i>when drivers are most likely to be using their phones.</i><p>I don't know about phone-use while driving laws in the US but in Australia, the fine of 3-4 hundred dollars for holding a phone at all while driving means there has to be some form of "hands-free" system in the car.<p>That means the driver isn't looking at the phone at all. Most cars these days have phone controls on the steering wheel, some form of bluetooth phone-car connectivity, and also voice-controlled phone usage such as "Call MaryLou."