Research on visibility of traffic sign in nighttime and development of new materials for traffic sign system

摘要

The driver's visual recognizably of a traffic sign depends upon the variation of the visual environment in the dark night. And researches were made on the optimum condition of brightness to secure good visibility of a traffic sign board, which varies according to circumstances of the location of the sign post This paper proposes an application standard to install traffic sign which has been made based on the research results, and describes retro-reflective materials with extra-high-luminance and system of lighting a traffic sign, which are tested for attaining the optimum brightness on a road.