US high school students estimate they spend an average of 21% of each trip looking at their mobile phones while driving, according to a new study which surveyed more than 1,000 teenagers.

The teens estimated that 26% of these glances toward a phone lasted for 2 seconds or longer – about the time it takes to read or send a text message.

While these responses are likely are only an approximation of actual distraction, the authors of the study point to research which found that glances greater than 2s were associated with a 5.5 times greater likelihood of a crash.

“Distracted driving is a serious public health threat and particularly concerning among young drivers,” says lead author Dr Rebecca Robbins of Brigham and Women’s Hospital, USA. “Driving distracted doesn’t just put the driver at risk of injury or death, it puts everyone else on the road in danger of an accident.”

The researchers first conducted semi-structured interviews with 20 students to identify the beliefs, intentions, and behaviours influencing teenagers in the US to engage in distracted driving. The teenagers were recruited from high schools in the northeastern and western US in suburban and rural areas, rather than urban areas where they may be less likely to drive.

The responses were used to design a questionnaire which was completed by 1,126 geographically representative participants across the US.

The most common reasons for the distracted driving were entertainment (65%), texting (40%) and navigation (30%).

Responses indicate that many young drivers believe that distraction at the wheel is associated with negative outcomes, that their parents and friends think they should not drive distracted, and that their peers do so.

They also suggest that most teen drivers have a “strong belief” that they themselves can withstand the pressure to drive distracted.

“The findings from the study give us insights into the perceptions and beliefs from teenage drivers, which can be used to help create effective interventions to prevent distracted driving,” says Robbins.

“We found that, while young drivers recognise the advantages of using smartphone features like GPS, they also understand the heightened risk of accidents associated with distracted driving.

 “Encouraging the use of ‘Do Not Disturb’ mode, keeping phones out of reach and ensuring teens get adequate sleep are effective strategies to mitigate this dangerous behaviour.”                    

The researchers caution that the small sample size used for the semi-structured interviews “may not accurately represent the broader high school-aged driving population” and that “results may need to be replicated among urban adolescent drivers to ensure broader applicability”.

The study is published in the journal Traffic Injury Prevention.