With mobile phone distracted driving a growing road safety issue, a study reveals why some drivers slow down when using a mobile phone but others don't.

The author said mobile phone distracted driving was responsible for 25 per cent of car crashes in the United States and worldwide young drivers are overrepresented in using mobile phones.

"At least one in two young drivers in countries such as Australia, America and Canada use a mobile phone while driving," said the author who has just published his paper Self-regulation of driving speed among distracted drivers: An application of driver behavioural adaption theory in the international journal Traffic Injury Prevention.

"Current research reports that some drivers change their driving behavior when using a mobile phone; in particular they drive more slowly. However, until now we did not know whether this was an unconscious response to the increased workload or an active choice made by cautious drivers."

In a high-fidelity driving simulator at the speeds of 32 drivers aged 16-26 was measured while they held hands-free and handheld phone conversations or just drove.

Author said the drivers with little experience using mobile phones while driving tended to drive more slowly. Likewise, drivers who believe mobile phones are unsafe were found to drive more slowly while engaged in mobile phone tasks.

"Our research has identified that drivers who have a strong belief in their ability to successfully self-regulate mobile phone use might find themselves in more risky circumstances while performing lawful tasks such as hands-free conversations.

"This suggests that educational interventions could be oriented to the development of safety attitudes. Changing the design of mobile phones so it's harder to use them while driving could also help to minimise risk."

https://www.qut.edu.au/news/news?news-id=113664

http://www.tandfonline.com/doi/full/10.1080/15389588.2017.1278628