I have read the linked content. As you say the papers are not readily available.
Re the 1st link :
Observation 1 : "Conversation partners were told to tell one another a previously undisclosed "close call" story about a time their lives were threatened"
This would distract many....talking on a phone or in person. Human nature causes many to look at others faces when emotive recollections are shared. Odd this didn't seem to factor.
Observation 1 : The study happened to analyse the driving performance of 41
mostly young adult drivers.
It's those pesky youngsters being mentioned again !
Observation 2 : "Passengers took an active role in supporting the driver, often talking about surrounding traffic"
How helpful........
"So this guy followed me down an alley. with a knife"...(pause) .."STOP -THINK BIKE ! "....& then threatened to kill me"
Observation 3 : "That shared situational awareness could be helpful to the driver"
I am sure it was. Passengers that know me normally let me deal with the driving....I don't like brake pedal marks on my passenger mats.
Re 2nd link :
Only one observation : "Conversation on a cell phone did not result in compensatory performance adjustments, such as increasing headway or reducing speed "
I often drive slower and leave more gap if I have to use a hands free phone when driving. ..........Maybe I am the exception or maybe I am compensating, (for something)
2 weeks ago I carried two passengers. Both were talking to me. I nearly missed two junctions. This is unusual for me. Ironically the in car chat may have distracted me from my sat-nav.
I am not stating that in car technology is never a distraction, Technology can distract. A distracted driver can fail to see a hazard, fail to react in time & with serious or worse consequences. However, in post 66 I listed examples of multiple other distraction factors.....including the much lauded , (on here at least), good old fashioned road map. I noted the seeming lack of acknowledgment by some & thus have parked that lot for now.
Ideally drivers should drive with due consideration for their environment both inside & outside of the vehicle. If in doubt don't use it !
I am a self critical driver & far from perfect.
Thanks for the links