The application of mesopic vision models to street lighting

The potential efficiency gains to be obtained from the use of 'white' light to enhance the vision of the human eye at low (mesopic) light levels was investigated as part of a EC project to reduce the energy requirements for urban lighting. The emphasis is on checking that reduced illumination will not have any adverse effect on road user behaviour and road safety. Conclusions from a literature review are presented. An initial trial at TRL and a demonstrator installation at Albi, France are briefly described.