Dark Adaptation Time Study on Road Tunnel Daytime Lighting Based on Visual Performance Method

Abstract

Visual adaptation in road tunnel daytime driving is very important to driving safety and should be paid full attention. Visual adaptation consists of light-adaptation and dark-adaptation, daytime threshold zone dark- adaptation problem when driving from outside into the tunnel is more important in tunnel lighting, current studies have described significantly distinct in the length of adaptation time. This study simulates the daytime lighting environment in the road tunnel threshold zone and records the reaction time and pupil change to many test subjects according to visual performance method in the condition of the luminance from light condition (ambient exterior luminance 4000 cd·m^-2) and to dark condition (interior zone luminance 2cd·m^-2), through the data analysis the length of dark adaptation time is obtained (19.8s). Study on length of effective dark adaptation time can provide length basis for road tunnel threshold zone daytime lighting design.