Road lighting in residential roads should enhance the visual component of interpersonal judgements concerning the apparent intent of other pedestrianswhether friendly, aggressive or indifferent. This paper describes an experiment which collected forced-choice judgements of emotion and gaze direction after 1000 ms exposure under 18 combinations of lamp type, luminance and interpersonal distances. Better performance was found with higher luminance and larger task size, but with diminishing returns according to a plateau-escarpment relationship. The results were used to estimate appropriate light levels for outdoor lighting. Results for judgements of emotion from facial expression suggest a minimum luminance of the face of 0.1-1.0 cd/m 2 if facial expressions are to be identified accurately at 4 m, but a luminance above 1.0 cd/m 2 for identification at 10 m.

This article investigates different approaches to the interpretation of eye-tracking video records of pedestrians walking outdoors to determine the apparent importance of fixation on other pedestrians and how this is influenced by the frequency of occurrence. The three approaches were as follows: the proportion of time that fixations were on pedestrians (14%), a common approach to interpretation; the proportion of fixations at critical moments that were on pedestrians (23%), critical moments being defined by a delayed response to a dual task; and the probability of an approaching pedestrian being fixated at least once (86%). These data were compared against the number of pedestrians encountered during the trials; the proportion of all fixations and the probability of fixating people were affected by the number of people encountered -only the critical-fixations data did not exhibit a trend.

A recent study examined how luminance and spectral power distribution affect recognition of facial expression, a proxy for pedestrians' judgements concerning the apparent intent of other people. This paper describes a repeat study which included a greater number of test luminances, a third type of lamp, and an additional, shorter duration of observation (500 ms). Luminance and distance had significant effects on expression recognition; the effect of lamp was not significant and the effect of duration was suggested to be significant only within the escarpment region of the performance versus luminance relationship. The results were used to estimate appropriate light levels for outdoor lighting. A luminance of 1.0 cd/m 2 permits facial expressions to be identified with a 50% probability of correct identification at a distance of 15 m.

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After dark, road lighting should enhance the visual component of pedestrians' interpersonal judgements such as evaluating the intent of others. Investigation of lighting effects requires better understanding of the nature of this task as expressed by the typical distance at which the judgement is made (and hence visual size) and the duration of observation, which in past studies have been arbitrary. Better understanding will help with interpretation of the significance of lighting characteristics such as illuminance and light spectrum. Conclusions of comfort distance in past studies are not consistent and hence this article presents new data determined using eye-tracking. We propose that further work on interpersonal judgements should examine the effects of lighting at a distance of 15 m with an observation duration of 500 ms.