Sight distance analysis on dry pavement during nighttime addressing wildlife crashes on two-lane rural roads

Highway Geometric Design criteria are based primarily on daytime driving conditions ignoring nighttime driving. The present paper aims at filling part of this existing gap by presenting an analysis on the Available Sight Distance (ASD) at night and its relationship to horizontal geometric design on dry pavements of two-lane rural roads. The sight distance analysis was based on the Relative Visual Performance model (RVP) and covers all three groups of the driving population; young, middle-aged and older drivers. Two different vehicle headlamps (High Intensity Discharge-Xenon and Tungsten-Halogen) were taken into account compared the drivers’ ability to identify a possible obstacle. As obstacles were used two common wildlife animals, which present real-life hazards caused, increased rates of mortalities on roadways in U.S.A. and Greece, at night. Namely these are the white-tailed deer (Odocoileus virginianus) and the domestic goat (Capra aegagrus hircus) respectively. In the present study an effort has been made to approach the worst luminance driving scenario by presenting the minimum safety levels of driver’s visibility at nighttime.