explaining once more one part... The paragraphs on _standards_ at the end of the draft (norm is probably not the right word in English for technical rules) are perhaps not quite clear. What I meant was that the proper metrics for standards would be stating just minimum recommended values of spot luminance or illuminance and demanding no _bottom_ values for the _average_ luminance/illuminance. On the contrary, the average luminance/illuminance should get an _upper_ limit. This is an obvious conclusion from the physiology of vision. Quality lighting is done by having the average as close to minimum as possible. Of course, light pollution would be minimised this way too, by perhaps one third compared to the best existing lighting installations, but much more (several times, quite usually) for the overlit streets and roads. As the current standards contain recommended _bottom_ values of average pavement luminance/illuminance, the emissions from lamps to the roads (UF) are maximised. This maximises pollution as well. And does not help visibility. Visibility is given by the minimum light levels which are in the field of view, and made worse by glare from brighter parts of the scene, including the brighter parts of the road itself. Also, the attention of drivers is distracted by bright spots, which have no true information value (concerning the very road surface or obstacles). The _upper_ limit for average, or even for the maximum spot values of luminance/illuminance should be contained in laws too, as only these are obligatory, standards are not. This is the case in some Italian regions already. The drawback there is, that designers try to reach these upper limits for averages (as standards want them), instead of being content when reaching the sufficient minima of spot luminance/illuminance. (and a remark on TI: Limiting the TI should be done for people wearing a peak (sun visor), or for drivers using the sun visor of the car. Then the very steep emissions from luminaires would have no impact (they are easily blocked by the visor for angles less then 65 degrees from nadir), just the less steep ones would. An advantage of common FS luminaires (those with a flat glass, which helps to reduce emissions in counterproductive angles) would be much more manifested, esp. for the common old pole distances of less than 4, or even 3 heights. Lower pole distances enable really non-glare lighting. ) jenik