Effect of drivers' age and push button locations on visual time off road, steering wheel deviation and safety perception.

The study examined the effects of manual control locations on two groups of randomly selected young and old drivers in relation to visual time off road, steering wheel deviation and safety perception. Measures of visual time off road, steering wheel deviations and safety perception were performed with young and old drivers during real traffic. The results showed an effect of both driver's age and button location on the dependent variables. Older drivers spent longer visual time off road when pushing the buttons and had larger steering wheel deviations. Moreover, the greater the eccentricity between the normal line of sight and the button locations, the longer the visual time off road and the larger the steering wheel deviations. No interaction effect between button location and age was found with regard to visual time off road. Button location had an effect on perceived safety: the further away from the normal line of sight the lower the rating.