Hands-free calls while driving have long been considered safer than hand-held as they allow drivers to keep both hands on the wheel and their eyes on the road, reducing some of the physical and visual distractions associated with hand-held calls.
However, even though the physical act of holding a phone is eliminated, the mental distraction of hands-free calls still diverts attention away from the road and increases the risk of accidents.
Ruth Purdie, chief executive of the UK’s Road Safety Trust, said recently that evidence shows that hands-free is just as dangerous as physically using a mobile/cell phone.
“The cognitive distraction can increase crash risk, reduce hazard detection and lead to poor situational awareness,” she said.
She was backed up by Gemma Briggs, Professor of Applied Cognitive Psychology at the UK’s Open University, who said: “Research demonstrates emphatically that hands-free phone use is no safer than hand-held phone use.”
Worryingly, Dr Briggs added that the increased risk to drivers continues after the call has ended – for up to five minutes. She said: “People are largely unaware that their minds wander like this, or that it can affect their driving.
What the research says
A study published in the New England Journal of Medicine found that using a cell phone increased the risk of having a motor vehicle collision by four times. The authors reported that this relative risk increase was similar to the hazard associated with driving with a blood alcohol level at the US legal limit.
Crucially, the authors stated: “We observed no safety advantage to hands-free compared with hand-held.”
The US National Safety Council (NSC), meanwhile, has collated findings from a range of researchers. It includes the following:
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Drivers using hands-free and hand-held cell phones fail to see up to 50% of the information in their driving environment. This is known as ‘inattention blindness’ and causes drivers to miss exits and run through red lights and stop signs.
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Drivers using cell phones (handheld or hands-free) had slower reaction times than drivers impaired by alcohol at a .08 blood alcohol concentration, the legal limit in most US states.
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Listening to the other person during a cell phone conversation decreased activity in an area of the brain associated with driving by 37%.
Reaction times are slower
These findings are backed up by a study conducted by Dr Shimul Haque used Australia’s Centre for Accident Research and Road Safety, which used a driving simulator to measure the effects of using a mobile phone on reaction time and driving performance.
He says: "We exposed a group of drivers to a virtual road network which included a pedestrian entering the driver's peripheral vision from a footpath and walking across a pedestrian crossing.
"We then monitored the driver's performance and reaction times during hands-free and hand-held phone conversations and without."
For drivers conducting a conversation using either a hand-held or hands-free mobile phone, driver reaction time was over 40% longer than those not using a phone at all.
Dr Haque also alluded to inattention blindness, saying that when extra information is sent to the brain via a conversation, the brain compensates by not sending some visual information to the working memory. This results in distracted drivers looking at, but not ‘seeing’ some objects.
Modern technology adds to the problem
A study conducted in Perth, Western Australia, noted that new vehicles tend to be equipped with Bluetooth technology, facilitating voice activation and hands-free phone use.
The authors reported: “Though this may lead to fewer hand-held phones used while driving, our research indicates that this may not remove the risk. Importantly, if this technology increases mobile phone use in cars, it could contribute to even more crashes.”
Nor does the development of AIs like Siri provide a safer option. A study by Danish researchers found that interacting with Siri while driving is likely to be “unsafe for most participants, especially less experienced drivers”.
The authors of the study found that participants were distracted by Siri, compounded by frequent time-outs by the app when waiting for a response from a driver occupied with the road environment.
Speech-recognition quality in a noisy car, as well as problematic multi-lingual speech recognition in general, are other issues that resulted in cognitive distractions.
The challenge for employers
Changing drivers’ perceptions is going a challenge for organisations. In its 2023 survey, Swiss organisation BPA looked at the opinions of the Swiss population on the dangerousness of certain behaviours on the road.
And while 95% of motorists believe that driving under the influence of drugs is dangerous, telephoning with a hands-free device was only considered a ‘very dangerous practice’ by 5% of motorists.
“Motorists clearly underestimate the dangers of using this type of device when driving,” said Christoph Jöhr, Head of Road Behaviour at the BPA.
“Telephoning in this way significantly increases the risk of an accident. Indeed, when the driver's attention is distracted, the reaction time lengthens, which means that the stopping distance also increases.”
Conclusion
While hands-free calls are widely regarded as a safer option when compared with hand-held calls, this has been exposed as a myth. Any type of call while driving is hazardous, and it’s therefore essential that drivers eliminate such distractions while operating a vehicle.
Driver education is key, as is the monitoring and limiting of phone calls when behind the wheel. This process may take time, but employers have a duty of care to their drivers and the more people that are aware of the dangers of hands-free calls, the safer roads will be.
