>So you are saying, talking to a passenger "causes the same attention impairment level as someone under the influence of alcohol."? That is not what they said

>So you are saying, talking to a passenger "causes the same attention impairment level as someone under the influence of alcohol."? That is not what they said at all. They are correct in pointing out that there is a great deal of evidence that conversing on a cell phone (even hands free) while driving is as dangerous as being intoxicated while driving. There have also been studies that investigated why talking hands free on a cell phone is more dangerous than conversing with a passenger. For example: From "Passenger and cell phone conversations in simulated driving" [1]: "The results show that the number of driving errors was highest in the cell phone condition; in passenger conversations more references were made to traffic, and the production rate of the driver and the complexity of speech of both interlocutors dropped in response to an increase in the demand of the traffic. The results indicate that passenger conversations differ from cell phone conversations because the surrounding traffic not only becomes a topic of the conversation, helping driver and passenger to share situation awareness, but the driving condition also has a direct influence on the complexity of the conversation, thereby mitigating the potential negative effects of a conversation on driving." [1] https://www.ncbi.nlm.nih.gov/pubmed/19102621 https://www.ncbi.nlm.nih.gov/pubmed/19102621