Road traffic signal lamp lights, besides should be satisfied with the general requirements of the traffic lights should also be satisfied with the following requirements: (1) the diameter of the shiny surface has surely, divided into two 200 mm and 300 mm, exterior brightness shall be as evenly as possible. Colors are red, yellow and green, and sometimes white. The false appearance that occurs when the sunlight slanting on the light surface of the lamp is reduced by means of the cap.

Road traffic signal light to declare a single color of traffic light, request: the light intensity: in the set brightness 104cd/m2, at the sight of 100m, red light is 200cd, the red yellow and green trichromatic intensity ratio is 1:1.3:5. In addition to the city expressway and the city with bright scenery, the light intensity can be lower in the evening, so it can be used for 200cd and 50cd. (2) the light intensity distribution: light spread the left and right sides is symmetrical, in the light intensity to 50% of the peak intensity of the light, should be in the optical axis around each 5 ° ~ 10 ° and below 7 ° direction.

The picture of the symbol signal lamp is to put the person, the bicycle, the arrowhead and so on the way that USES the silhouette is placed on the round lamp mouth, the silhouette part glows, the surroundings does not shine. Picture planning is necessary to cut for the pupil larger or abnormal refraction errors such as myopia occurrence of the phenomenon of astigmatism ─ ─ a similar in rain, fog reduced by halo sign identifiable degree)