Samenvatting
The speed and density of today's traffic requires great attention by road users. Light signals must be immediately recognised. Rising costs of energy and production force the industry to increase the durability of light sources, to increase luminous efficacy and to decrease the energy and maintenance costs. New developments show that the improvement of lamps for road traffic signals is ongoing, but more research is needed. For the covering abstract of the conference see IRRD abstract no 244569.