An experimental apparatus of traffic signs with LED was designed .Identification and legibility of traffic signs were studied in three illuminance and contrast conditions .The effect of illuminance and contrast of signs on pedestrians ’ visibility was analyzed and the apparent expansion phenomenon of signs was discussed .The experimental results showed that: 1 ) the identification of subjects increases as the illuminance and contrast increases;2 ) sign recognition rate of older subjects was influenced by the visual function, the identification of subject decreases as the illuminance increases when the contrast was bigger and recognition distance was more than 30m;3 ) there was an apparent expansion phenomenon of traffic signs during focus sign , and there was remarkable tendency for older subjects comparing with younger subjects when the sign illuminance was more than 500lx.%设计了一种LED交通标志的视认性实验装置，采用三种表面照度和对比度研究交通标志的视认性和易读性。分析了表面照度和对比度对行人视认性的影响，探讨了视认标志的视膨胀现象。结果表明：1）表面照度和对比度越高，视认率越高；2）年长者的标志视认率与其视觉功能有关，当对比度较大且视认距离在30m以上时，增加表面照度，其视认率下降明显；3）视认过程中存在视膨胀现象，标志表面照度在500lx以上时年长被试者比年轻被试者表现的更明显。
展开▼
