五十年代,美国3M公司的帕姆契斯特成功地利用微粒玻璃珠研制反光膜材料,反光膜标志便开始取代一般涂料标志,成为第二代交通标志的主要材料,在世界各地广泛地采用,初步解决了夜间行车道路标志不明显的问题。但是反光标志膜在有些情况下仍显示出不足,一是能见度差的时候,比如雾、雪天气;二是在驾驶员开近光灯行驶的时候。以上两种情况下均不能使驾驶员获得足够的安全距离,因此国外许多研究部门和厂商均力求解决这一问题。在解决这一问题的诸多 In the 1950s, the United States 3M company’s PamCaster successfully using reflective glass particles glass beads, reflective film logo began to replace the general paint mark, a second generation of traffic signs of the main material used widely around the world , Initially solved the problem of not obvious road signs at night. However, reflective sign film still shows some deficiencies in some cases, one is poor visibility, such as fog, snow and weather; the second is driving the driver near the light when driving. In both cases, drivers can not get enough safe distance, so many foreign research departments and manufacturers are trying to solve this problem. There are many solutions to this problem