akirk wrote:
however I don't think that anyone is arguing to allow mobile phones other than hands-free
and (without knowing the stats) presumably there are not overwhelming stats to show that hands-free use is causing accidents / killing people - even if it is not optimal...
I am sure that we all agree that optimal conditions in the car include no distractions - but, while I might go out for a drive with others from here and have that level of focus, the reality of real life is far from ideal...
There are evidence. The distraction is caused by talking over the phone, rather than by taking one hand off of the wheel to hold it. A lot of people take a hand off of the wheel with no adverse consequences, so that isn't the reason why using a phone is dangerous.
akirk wrote:Or talk to your passengers
Or listen to the radio
Or think about / plan / go over conversations or issues at work
Or be angry / tired / frustrated / excited / etc.
Or have low blood pressure through not having eaten recently
Or eat while driving to avoid low blood pressure
Or eat a sweet or anything above functional fuel
Or smoke
Or drink (fluids)
Or drive for more than xxx (insert optimal time per person) in one stage
Or be conscious of needing the loo
Or driving with a cold / under the weather
Or...
Talking to passengers is wholly different than talking on the phone. Empirically, most researches don't make it out to be very noteworthy in terms of causing collisions. Explanations include the fact that the passenger is aware of the road, so the flow of the conversation is governed by the hazards that the passenger is also aware of.
Also, if the passenger is visible to the driver even out of the corner of the eye, than it's quite different to when the discussion is being made purely over the phone where you are only conversing with a voice, and the other gestures involved with speech are imagined by the mind. Hence, the distracting effect of talking on the phone persists for a few minutes after the phone is hung up.
It's not too bad. If the driver simply slows down a bit, he or she can compensate for the prolonged reaction time. In situations that demand particularly high levels of concentration, it's best to cut off the flow of the conversation ("just a moment"). I wouldn't opt to make it illegal.
As for the other conditions you mentioned - some of them are also problematic. Drinking while driving, for instance, is quite perilous. Not only is it immensely distracting to stabilize the bottle while the car is moving (depending on how winding or bumpy the road is - a passenger might not even succeed in doing it), but if anything even remotely surprising happens - the driver will aspirate and choke.
Driving more than a fixed number of hours - concentration does deteriorate quite rapidly over time. Think about a tough class back at school - did it never happen that your attention was exhausted after as little as 40-50 minutes?
Driving with a cold is extremely perilous. It is equally as dangerous as driving well above the legal drink-drive limit.