symmetric lighting, <in a road tunnel>
lighting design technique where the light equally falls on objects in directions with and against the traffic
Note 1 to entry: Symmetric lighting is characterized by using luminaires that show a luminous intensity distribution that is symmetric in relation to the plane normal to the direction of the traffic.
Note 2 to entry: See also "pro-beam lighting", "counter-beam lighting".
Note 3 to entry: This entry was numbered 17-1293 in CIE S 017:2011.