This part of BS 5489 gives recommendations on the design of the lighting of tunnels for motorized and mixed traffic. It is applicable to all types of road including motorways.
It gives recommendations for those aspects of lighting that are concerned with traffic safety, such as arrangements, levels and other parameters including daylight. It does not give recommendations for aspects of lighting that concern visual comfort.
This part of BS 5489 excludes the lighting of underpasses or subways reserved for pedestrians or cyclists, which is covered in BS 5489-1.
NOTE This part of BS 5489 is based on photometric considerations, and all values of luminance and illuminance are maintained values.