New Zealand too. If you want to make calls while driving, you have to have a hands-free system. It baffles my mind that there are countries in which people can legally interact with their phone while driving.
https://www.distraction.gov/downloads/pdfs/the-impact-of-han...
http://www.nsc.org/DistractedDrivingDocuments/Cognitive-Dist...
http://www.bbc.com/news/uk-36475180
http://www.nsc.org/learn/NSC-Initiatives/Pages/distracted-dr...
For sure there is a distraction, but it is definitely not on the level you described.
Result: Driving drunk, with a cellphone or with a hands-free phone were all equally dangerous. I'm as surprised as you must be.
They didn't test talking to a passenger, but I'm of the opinion that laws don't forbid what is de-facto considered as normal by most people. Besides, talking to a passenger isn't verifiable.
Last thing, I sure remember unfolding my map over the wheel on the highways, so despite what the police says about vocal GPS apps, they're still 100% better for me.
Also driving while short on sleep. IIRC it's something like ~20 hours awake approximately matches .08 BAC, not sure offhand how chronic sleep deprivation (like most adults have) factors in.
(My conclusion from all this is that alcohol should not be treated as a special case: if you can't drive safely, proving that it must be for some other reason shouldn't get you out of trouble.)
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."
We're just not very good at that.
Even better is what I'm increasingly seeing in states that have made texting/hands-on phone use illegal. Of course people still do it - except now they hold the phone down low so they don't get caught. Of course, that means that they can't keep the road in line of sight for however long it takes to finish their business.
Best of all [1]: in cases where this leads to an accident, phones are hidden more quickly than they were since usage is against the law - which means phone usage will get underreported in accidents. That'll create a nice echo effect where it looks like the law is helping. The apparent number of phone-related accidents will drop - while total incidents will remain the same or increase.
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4001674/ - or so some of the numbers here can be interpreted. As the authors repeatedly point out, though - there are so many variables that it's difficult to draw any meaningful conclusions.