Using a hands-free kit while driving is just as distracting as holding the phone, researchers claim

Reaction time for both methods is 40% longer than those who don't use phones
Experts say it is the conversation that distracts drivers, not holding a device
The brain power needed to hold conversations alters visual scanning patterns

Published: 17:44 EST, 13 December 2016 | Updated: 18:09 EST, 13 December 2016

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Using your smartphone in hands-free mode while driving is found to be just as distracting as holding the device in your hand, researchers have warned.

A new study reveals the reaction time of drivers using either method was more than 40 percent longer than those who refrained altogether.

The team believes that the increased brain power needed to hold a conversation over the phone is what alters a driver's visual scanning pattern - not the device itself.

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Using your smartphone in hands-free mode while driving is found to be just as distracting as holding the device in your hand, researchers warn. A new study reveals the reaction time of drivers using either method was more than 40% longer than those who refrained altogether

HOW WAS THE STUDY DONE?

Researchers from Queens University of Technology instructed a group of volunteers to participate in a virtual road simulation.

This included a pedestrian entering the driver's peripheral vision from a footpath and walking across a pedestrian crossing.

The team monitored the driver's performance and reaction times during hands-free and hand-held phone conversations and without.

The reaction time of drivers participating in either a hand-held or hands-free conversation was more than 40 percent longer than those not using a phone.

There is an 11m response to the pedestrian crossing while the driving is travelling at 40km/h.

Dr Shimul (Md Mazharul) Haque, from Queens University of Technology (QUT) School of Civil Engineering and Built Environment and Centre for Accident Research & Road Safety, presented findings at a Driving Distraction Seminar held at QUT in November.

For this study, Dr. Haque measured the effects of mobile phone distraction on safety.

This included reaction time and driving performance of subjects in the CARRS-Q Advanced Driving Simulator, which gives researchers the ability to study driver behavior in different driving conditions.

With this technology, researchers can explore these conditions with a high degree of realism, but without the risk of subjects crashing.

The simulation has been used to study impaired drivers, road conditions and environment, human machine interface and more.

'We took a group of drivers and exposed them to a virtual road network which included a pedestrian entering the driver's peripheral vision from a footpath and walking across a pedestrian crossing,' Dr Haque said.

'We then monitored the driver's performance and reaction times during hands-free and hand-held phone conversations and without.'

'The reaction time of drivers participating in either a hand-held or hands-free conversation was more than 40 percent longer than those not using a phone.'

'In real terms this equates to a delayed response distance of about 11m for a vehicle traveling at 40km/h.'

Experts believes that the increased brain power needed to hold a conversation over the phone is what alters a driver's visual scanning pattern - not the device itself. These new findings raise questions about the current laws and if mobile phones should be banned while driving

'This shows hands-free and hand-held phone conversations while driving have similar detrimental effects in responding to a very common peripheral event of a pedestrian entering a crossing from the footpath.'

Dr. Haque found that it wasn't the holding the phone that causes drivers to become distracted, it is the actual conversation.

'It appears that the increased brain power required to hold a phone conversation can alter a drivers' visual scanning pattern.

TALKING WHILE DRIVING DRAINS YOUR BRAIN

Researchers found the simple act of having a conversation while driving is such a drain on the brain that reaction times are slowed and hazards are missed.

Psychologists at the University of Sussex found that the area of the road that hands-free drivers concentrate on is up to four times smaller than the average road user.

On the first of two experiments, 60 men and women watched a video of a hazard-laden car journey while sitting in a driving simulator.

The volunteers, were told to hit the brake when they saw a pedestrian step out onto the road, a car badly parked at a junction or other hazard.

To mimic using a hands-free phone as they ‘drove’, some were played statements over a loudspeaker and asked to say whether they were true or false.

Sentences such as ‘cows have hanging ears’ were designed to make them draw a mental picture, while others, such as ‘the Battle of Hastings as in 1066’; were purely, factual in nature.

Those who were ‘on the phone’ spotted fewer hazards – and even failed to see potential dangers right in front of their eyes.

Those asked the imaginative questions did worst of all, spotting just half as many hazards as the undistracted drivers.

A second experiment used eye-tracking technology and showed that ‘motorists’ who were using their visual imagination focused on an area of road just a quarter of the size of that looked at by undistracted ‘drivers’.

And the results were on a par with those from studies into hand-held phones.

'In other words the human brain compensates for receiving increased information from a mobile phone conversation by not sending some visual information to the working memory, leading to a tendency to 'look at' but not 'see' objects by distracted drivers.

'The distraction of a mobile phone conversation is not the same as an in-car conversation with a passenger because the non-driver can alter their dialogue based on the driving environment, for example stop talking when approaching a complex driving situation.'

These findings raise questions about the current mobile phone use laws in Queensland, which only ban hand-held use and not hand-free devices, said Dr. Haque.

IT TAKES 27 SECONDS TO REGAIN ATTENTION AT THE WHEEL

Using your phone in hands-free mode could still be putting motorists and pedestrians at risk.

It takes up to 27 seconds for a driver to regain full attention after issuing voice commands, researchers have found.

Experts have warned that just because the ability to use voice commands - such as Siri and Cortana - are available to use in the car, doesn't mean they should be used.

In one of the two studies conducted, scientists found that it was 'highly distracting' to use hands-free voice commands to dial phone numbers, call contacts, change music and send texts with Microsoft Cortana, Apple Siri and Google Now smartphone personal assistants.

Google Now was found to be slightly less distracting than the others. The second study examined voice-dialling, voice-contact calling and music selection using in-vehicle information or 'infotainment' systems in 10 model-year 2015 vehicles.

Three were rated as 'moderately distracting', six as 'highly distracting' and the system in the 2015 Mazda 6 as very 'highly distracting'.

He said in addition, the study also found the reaction time of provisional licence holders was double compared to those who held an open licence.

'Despite provisional licence holders in this study averaging a driving experience of more than two years, the detrimental effects of mobile phone distraction showed P-plate drivers had an increased probability of failing to detect a pedestrian.'

Dr Haque said the distraction of mobile phone use also had an impact on driver braking behavior.

'Distracted drivers on average reduced the speed of their vehicle faster and more abruptly than non-distracted drivers, exhibiting excess braking,' he said.

'While the driver is likely to be compensating for the perceived risk of talking and driving, the abrupt or excessive braking by distracted drivers poses a safety concern to following vehicles.

'Again these findings highlight a need to consider mobile phone use laws in response to interventions to reduce rear-end crashes.'