先天色覚異常者におけるLED式道路交通信号灯色の見え方

Perception of road traffic lights using light-emitting diodes by congenitally color-defective persons

　先天色覚異常者におけるlight-emitting diode （LED）式道路交通信号灯色の見え方について検討する目的で，LED式および電球式信号灯のシミュレーション装置を試作し，色覚正常者5名，先天色覚異常者18名に対し検査を施行した。その結果，色覚正常者では誤答はみられなかった。先天色覚異常者では，LED式，電球式ともに18名中11名（61％）に誤答がみられた。誤答率は赤および黄で，電球式に比べてLED式において高い傾向がみられた。したがって，LED式道路交通信号灯においては，先天色覚異常者においても容易に見分けられるような色以外の情報を要するものと思われた。

We evaluated the ability of congenitally color-defective persons in discriminating among red, yellow and green traffic lights using light-emitting diodes (LED). We built two traffic light systems. Incandescent light bulbs were housed in one and LEDs in the other. The two systems were presented to 5 normal persons and 18 color-defective persons as test subjects. The 5 persons with normal color vision gave correct answers regarding red, yellow and green. Out of 18 color-defective persons, 11 (61%) gave false answers both for LED and incandescent lights. The inci-dence of false answers was greater for red and yellow by LED than by incandescent lamp. The findings show that a ma-jority of color-defective persons have difficulties in distinguishing LED road traffic lights. There is an urgent need to incorporate additional signs in the traffic light system.