| 摘要 |
PURPOSE:To enable efficient lighting in a tunnel where the traffic density is light. CONSTITUTION:A luminaire is used, which has an optical system A for effectively informing time driver of an automobile coming close to a tunnel of the linear shape of the road inside a tunnel and an optical system B for effectively elevating the lightness of the road inside the tunnel. In case that the temporal average value of the traffic density inside the tunnel after a certain time is estimated to be above a certain value from the measure results of a traffic density measuring device 12, both of the optical systems A and B are lit by a controller 13. Hereby, a driver can perceive not only the linear shape of the road inside the tunnel but also the existence or nonexistence of an obstacle on the road inside the tunnel. On the other hand, in case that the temporal average traffic density is estimated to fall from the above value from the measure result of the traffic density measuring device 12, only the optical system A is lit by the controller 13. As a result, though he can not perceive the road inside the tunnel or the obstacle on the road, he can perceive time linear shape of the road inside the tunnel being the minimum visual requirement in safe running. |
