A12. Cost effective public lighting

The purpose of street lighting is to improve the safety and amenity of roads at night. For main roads the emphasis is on safety for all types of road user, motorists, cyclists and pedestrians. An effective installation should enable a motorist to see the outline of the road, reveal junctions and enable him to see any obstacle on the carriageway. This is done by providing a fairly high, and reasonably uniform, road surface brightness which will form a background against which any object can be seen in silhouette. This must be achieved with as little glare from the light source as possible as this has the tendency to distract the attention of the observer from his view of the road ahead.