Environment and roads

How much light is needed?

The level of lighting required depends upon the task to be undertaken. There needs to be enough light to ensure that the task can be performed safely. In general national bodies including British Standards, The Institution of Lighting Engineers (ILE) and The Chartered Institution of Building Services Engineers (CIBSE) prescribe average and minimum lighting levels. It is also important not to over light, to control energy consumption and avoid light pollution / spill.
As a guide the following table gives examples of lighting levels:

Typical light requirements

Task Undertaken	EH(ave) Lux	EH(min) Lux	Uniformity Ratio
Residential estate access road with moderate night-time public use (road, verge & footpath)	6.0	2.5
CCTV coverage	20 to 25	10 to 15
Lawn tennis, recreational over court	180		0.5
5-a-side football	50		0.25
Car park in an urban area	30	10

EH (ave) is the maintained average horizontal illuminance on the surface
EH (min) is the maintained minimum horizontal illuminance on the surface
Uniformity ratio the ratio of the minimum illuminance over a given area to the average illuminance