Tunnel lighting

Tunnels are now common in both roadway and train way. Lighting design in tunnels attracts importance keeping safety and comfort in mind. Light source position, brightness pattern, intensity etc. are very important parameters to take care of while designing the lighting system inside tunnels. Any design should be in such a way to produce automatic adaptation of driver’s eye while approaching, traveling through and leaving the tunnel. Diver should feel safe and comfort. During day time, since external brightness (outside the tunnel) is very much greater, brightness pattern has to be changed from that of night timing, where brightness outside is very less. Thus we require two lighting schemes in tunnel- one for day time and one for night. Lights with longer life span have to be used to avoid frequent replacements. Light fittings should be in such a way that skilled workers can perform maintenance work easily. The optimum spacing between lights at the entry level and exit level is around 2 meter and inside the tunnel around 4 meter.