Driving and telephoning: Relative accident risk when using hand-held and hands-free mobile phones

Experimental research shows that using mobile phones while driving leads to impaired driving, and it has been suggested that this driving impairment to a large extent is a result of cognitive, rather than physical, distractions. This notion is partly supported by empirical data showing that use of handsfree phones is associated with impaired driving in much the same way as use of hand-held phones. In the present study, accident risk when using hand-held and handsfree phones was investigated in a sample of 4307 drivers who were involved in accidents in 2007. In addition, data from a similar survey from 1997 (N = 5007) were used in order to get more observations. Relative risk was estimated using "quasi-induced exposure" in multiple-vehicle accidents. Results from the two surveys combined showed a significant increase in accident risk for hand-held mobiles and for hand-held and handsfree phones together. A non-significant tendency towards increased risk for hands-free mobiles was also detected. However, analyses of data from 2007 separately did not result in statistically significant relative risk estimates for any of the mobile types. Hand-held users were more inclined to attribute the accident to mobile phone use than were handsfree users. (c) 2010 Elsevier Ltd. All rights reserved.