Driving with an illegal or almost-illegal level of blood alcohol is often no more dangerous than taking a call using a hands-free device at the wheel, according to new research by scientists in Australia and Spain.
Sumie Leung Shuk Man of Barcelona uni carried out the study in cooperation with colleagues Down Under. He and his fellow researchers tested human subjects' skills in a driving simulator, first under the influence of alcohol and then while handling phone calls on hands-free rigs. They also measured the effects of answering text messages.
"When the conversation using the handsfree was simple, the effects were comparable to a BAC level of 0.4 grams per litre, which is below the legal limit of 0.5 g/l in countries like Spain and Australia," said the prof.
"However, when more attention was required, their alcohol level analogue shot up to 0.7 g/l, which is above the legal limit in both countries."
With a 0.7 blood alcohol level you would just barely be shaving in under the legal limit in the US or UK, indicating that in plenty of cases towards the demanding end of the spectrum accepting a call would be as dangerous as drunk driving even in the more relaxed jurisdictions.
"When answering text messages, the rate stood at 1 g/l, which is illegal in any of all of these countries," added the scientist.
Of course, driving with such blood-alcohol levels will lead to severe legal penalties: whereas taking a call using a handsfree device will not. And while texting at the wheel would perhaps lead to a a charge of driving without due care and attention or similar, it's typically hard for police officers to spot a texting driver and the offence generally goes unpunished.
Of course, the use of hands-free communications (and other technology) while driving is becoming more and more commonplace and despite fulminations from various quarters there isn't any realistic prospect of stamping it out. Many people, indeed, would point out at this stage that in days of old people used to bowl merrily along the road while fiddling with radio tuners, groping about for tape cassettes and generally acting like a danger to all around them: by contrast, pressing a single button on dashboard or wheel and then holding a conversation would seem quite safe and reasonable.
Even though handsfree talking is every bit as dangerous as driving "drunk" ... something which people also used to do all the time, but which is nowadays condemned as the very worst of evil behaviour.
In their paper, published in the journal Traffic Injury Prevention, Leung and his colleagues conclude:
Very simple conversations on a mobile phone may not represent a significant driving risk (compared to legally permissible BAC levels), whereas cognitively demanding, hands-free conversation, and particularly texting represent significant risks to driving.
"Our results suggest that the use of handsfree devices could also put drivers at risk. Although they should be allowed, they require more research to determine how they should be regulated," concludes Dr Leung.
No matter how that pans out, though, there would seem little chance of the drink-driving limits being revised - at least until the self-driving car comes along. ®