| 摘要 |
<p>The road stud has rounded end shoulders, reflecting surfaces, and flat crown, forming an external transparent envelope of which the internal surface has been treated with metal. Beneath the transparent surface are three sided prism reflectors which send back horizontal rays along their original path, and the hollow part of the stud is filled with a compact material resistant to pressure. Water and fine dirt road washings are kept clear of the reflecting surface by an entry ridge and all surfaces of the stud apart from the reflecting surfaces are given an anti-skid treatment.</p> |
