California Partners for Advanced Transportation Technology

The goal of this project was to design, implement, and validate a computerized Glare Meter Tool that could be used in the field to assess the level of glare from headlights of opposing vehicles in a variety of situations, without relying on subjective reports of observers. Both disability glare and discomfort glare were addressed. The net result is an instrument that is capable of acquiring an image of a scene with glare, then analyzing the image to output a number on the standard, widely-used De Boer Rating Scale for Evaluation of Discomfort Glare, and also an equivalent veiling luminance that can be used to assess the level of disability glare. The Glare Meter Tool has been demonstrated to provide accurate results in both laboratory and field experiments, but at the current level of development, its practical use in the field is compromised by dynamic range limitations and exposure time requirements.