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Field and computer-simulated evaluation of head lamp beams

In: Transportation Research Board Special Report, No. 156, 1975, p. 64-73

Authors: Rudolf G. Mortimer

The development of targets for use in field tests to measure visibility distances of drivers and to evaluate head lamp beams is described. The test procedure used appears to have satisfactory statistical reliability. The test provides discriminations in the visibility distances attributable to variations in head lamp beams. In addition, tests that evaluate glare effects to opposing drivers and those due to reflections in mirrors from the head lamps of a following vehicle are described. The development of a computer simulation model that predicts visibility distances and glare effects is described. Model predictions and the results of the field tests are compared and provide a good fit. Some examples of the use of this model to evaluate the effects of head lamp aim and various meeting beam patterns are described.