scope:

Limitations to the scope

This report describes models for predicting discomfort from glare, focusing on discomfort glare for drivers in the context of road and vehicle lighting, but does not present recommendations for thresholds that would restrict or reduce discomfort completely. The report focuses on dry road surfaces; while wet road surfaces present additional problems, there are insufficient data available to draw conclusions.

This report is based on CIE 031-1976 (CIE, 1976), CIE 055-1983 (CIE, 1983); CIE 112-1994 (CIE, 1994), CIE 115:2010 (CIE, 2010), CIE 136-2000 (CIE, 2000a) and CIE 146:2002 (CIE, 2002). In CIE 115:2010 (CIE, 2010a), CIE 132-1999 (CIE, 1999), CIE 140:2019 (CIE, 2019a) and CIE x023:2002 (CIE, 2002), discomfort glare is not considered as a quality criterion in the context of road lighting for drivers. In CIE publications on other areas of lighting, e.g. CIE 129-1998 (CIE, 1998) for outdoor workplaces or CIE S 021:2011 (CIE, 2011) and CIE 188:2010 (CIE, 2010b) for vehicle lighting, no differentiation is made between discomfort and disability glare. Because the effects of disability and discomfort glare are differently influenced by contextual factors they are considered as separate items in this report.

The current report also considers models developed for calculating glare in the context of sports lighting (CIE 112:1994) because these are based on discomfort.