Empirical StudiesBy J. Rogé, J. Ferretti, G. Devreux
The aim of this study is to test the effect of colour contrast between powered two-wheelers and other traffic on the ocular behaviour of young and old car drivers and on their ability to detect powered two-wheelers. Ten young car drivers (average = 23.3 years) and ten old car drivers (average = 57.8 years) used a simulator to follow a vehicle travelling through dense traffic on a carriageway. Whilst following this vehicle, the participants were required to detect the presence of a powered two-wheeler (ptw) filtering through the traffic in their rear-view mirrors. The sensory “conspicuity” of the ptw was varied by using high-contrast colours (red clothing, helmet and motorcycle body) or low-contrast colours (white clothing, helmet and motorcycle body) compared with other traffic (white vehicle bodies). By studying the visibility distance of the ptw (distance between the car driver and the ptw at the moment it is detected) and indices relating to the car driver’s ocular behaviour (frequency of glances and duration of prolonged glances in the rear-view mirrors), it was found that a high colour contrast only improves the conspicuity of ptws under certain speed and traffic conditions, and is dependent on the age of the car drivers. It is envisaged that these findings will have an impact on the safety of vulnerable road users (ptws), and will highlight the need to consider the age of car drivers in driving situations that require divided attention.