ABSTRACT
The aim of this study was to identify changes in driver behaviour due to a handsfree telephone conversation carried out during a motorway journey. Previous research has addressed the problem from a variety of viewpoints, using different independent and dependent variables within a range of test environments. Four studies (Quenault 1968, Wetherell 1981, Mikkonen and Backman 1988, Brookhuis et al 1991) indicate no driving performance change whilst using a earphone, and five (Brown and Poulton 1961, Brown et al 1969, Fairclough et al 1990, Alm and Nilsson 1990 and 1991) indicate change; most typically a reduction in driving speed, but also a decrease in ability to control the lateral path of the vehicle, and an increase in driver reaction time. Of the real road studies, changes in driving behaviour were associated with a driving task with high task complexity i.e. complex manoeuvres or urban traffic conditions.
