A two-part study of the influence of vehicle headlamps and roadway lighting on the ability of drivers to see pedestrians along crosswalks in roundabout intersections was conducted. In the first part of the study, the photometric performance of vehicle headlamp systems including conventional halogen and high intensity discharge (HID) low-beam headlamp systems and intelligent vehicle headlamp systems that might provide optimised illumination for navigating through roundabouts was compared. Relative visual performance analyses based on these comparisons were used to demonstrate when such vehicle headlamp technologies might offer benefits in terms of pedestrian safety and efficient navigation. In the second part of the study, an outdoor field experiment was conducted to assess observers' ability to detect and identify the walking direction of pedestrian targets in the field of view. Importantly, this experiment utilized many of the same conditions and geometric characteristics that were evaluated in the photometric simulation, and included calculations of visual performance. A secondary objective of the studies summarized in this report was to validate the use of visual performance modelling to predict driver visibility under conditions corresponding to illumination from vehicle headlamps and fixed roadway lighting. (Author/publisher)
Abstract