The effect of the driving activity on target detection as a function of the visibility level : Implications for road lighting

The Small Target Visibility model used in road lighting design is based on a strong simplification of the driving task. To specify the driver's visibility needs in a way consistent with state-of-the-art lighting engineering practice, a field experiment was designed in order to investigate target detection performances, comparing driver and passenger status conditions. Sixteen target visibility levels (VL) were used. In the driver status, 34 participants had to press a button as soon as they detected the target stimulus placed on the experimental lighted section. In the passenger status, the same participants had to detect the target stimulus while the experimenter drove. The results show that the passengers' performances (detection distance) were higher than the drivers' performances (p = .0014). Furthermore, the higher the VL, the higher the detection distance (p < .0001). These results lead up to modify the reference scenario in order to take into account human factor components for road lighting design