Washington:
Most smartphone personal assistants and in-vehicle infotainment systems are highly distracting to drivers, according to new research which found that it takes up to 27 seconds to regain full attention after issuing voice commands.
In two new studies by University of Utah researchers, participants drove various cars at 40 kph or less around a 4.3-km route in Salt Lake City's Avenues neighbourhood as they used voice-commands to dial numbers, call contacts and tune the radio using in-car systems, and to dial numbers, call contacts, choose music and text using smartphones.
One of the studies found that it is 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, though Google Now was a bit less distracting than the others.
The other 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 one was rated very highly distracting.
"Just because these systems are in the car doesn't mean it's a good idea to use them while you are driving," said University of Utah psychology professor David Strayer, senior author of the two new studies.
"They are very distracting, very error prone and very frustrating to use. Far too many people are dying because of distraction on the roadway, and putting another source of distraction at the fingertips of drivers is not a good idea.
It's better not to use them when you are driving," he said.
The studies also showed older drivers - those most likely to buy autos with infotainment systems - are much more distracted than younger drivers when giving voice commands.
But the most surprising finding was that a driver travelling only 40 kph continues to be distracted for up to 27 seconds after disconnecting from highly distracting phone and car voice-command systems, and up to 15 seconds after disconnecting from the moderately distracting systems.
"The lasting effects of mental distraction pose a hidden and pervasive danger that would likely come as a surprise to most drivers," said Peter Kissinger, President and CEO of the AAA Foundation for Traffic Safety, which funded the study.
"The results indicate that motorists could miss stop signs, pedestrians and other vehicles while the mind is readjusting to the task of driving," he said.