That moment to drop the phone is a moment you may not have (or more accurately, that your prospective victims may not have).
And the research is conclusive, to demonstrate that simply having the telephone conversation makes you unsafe, as much as drinking and driving impaired make you unsafe. A telephone conversation is not like listening to the radio, it's not like conversing with a passenger, and it's not like mumbling to yourself. It makes you an active threat to the safety of all around you, and frankly the best anyone can hope for is that you just kill yourself without harming anyone else.
And the research is conclusive, to demonstrate that simply having the telephone conversation makes you unsafe, as much as drinking and driving impaired make you unsafe. A telephone conversation is not like listening to the radio, it's not like conversing with a passenger, and it's not like mumbling to yourself. It makes you an active threat to the safety of all around you, and frankly the best anyone can hope for is that you just kill yourself without harming anyone else.