Presented at First international conference on driver distraction and inattention (DDI 2009), Gothenburg, Sweden, September 28-29, 2009

Behavioural adaptation refers to unintended changes in behaviour that follow a change to the road transport system. Legal restrictions on handheld mobile phone use may inadvertently encourage some drivers to use more easily concealed forms of electronic communication, such as text-messaging. An observational mobile phone use survey was conducted of vehicles stopped at intersections in the state of Victoria, Australia. The survey aimed to quantify Melbourne drivers’ use of hand-held and hands-free phones, as well as their engagement in a range of other non-driving activities that are associated with increased crash risk. Despite legislation prohibiting the use of handheld mobile phones while driving, a significant proportion of drivers (3.4%) were observed engaging in handheld mobile phone use, including text-messaging (1.5%). Conversely, only 1.4 percent of drivers were observed to be communicating via a legally allowed, hands free, device. While the observational survey was not designed to test the behavioural adaptation hypothesis, the results may suggest this possibility; however, further research is required before this can be established