| 摘要 |
A road marker 20 comprises a body 22. A photodetector 26 mounted on the body is responsive to illumination by headlights of a first vehicle approaching the body. The photodetector is connected in a circuit 32 on the body also comprising a light emitting device 30. The circuit being configured to energize the light emitting device upon illumination of the photodetector by the head lights of a vehicle approaching the body in a first direction A and the light emitting device is mounted on the body to enhance visibility of the body, particularly for a driver of a second vehicle being driven in a direction B other than the first direction. |
