Tunnel Lighting The BorderTransportationSystem may in some areas have tunnels and if highways are used as part of the system, then these tunnels must be lighted.  LED {Light Emitting Diodes} are the lamps of choice as each has a up to a 20+ year life expectancy* and uses very little electric. If highways are not used, but rail services are used only, then tunnel lighting can be optional, or set-up to only come on when a train is in the tunnel.   Lighting in the Stations and along the route can be used as needed, or when humans or machines are detected. * ~3-years if lit 24/7/365 Index of ... Learn About LED Bulbs LED Lighting Top 8 Things You Didn’t Know About LEDs