Despite its importance, very little is found in the literature on the visual tasks of pedestrians, particularly at night. This study was performed to identify and characterise the principal visual tasks of pedestrians at night and the key aspects of the visual environment that are important to pedestrians. In this study, an eye tracking method was employed. Wearing an eye tracker, subjects were asked to walk three different residential routes (5 subjects in day time and 15 subjects at night). In order to obtain further information about the experience of the subjects during the walk, a short interview was performed after completion of the task. The results show that whilst pedestrians may spend between 40% and 50% of their time looking at the footpath, not all of that time is spent on critical visual tasks. Looking at other people appears to be important to pedestrians but during this study the amount of time when subjects fixated on other people was limited. The apparent importance of the visual tasks away from the footpath compared to the tasks on it raises questions about how appropriate it is to specify the lighting on residential road using illuminance on the road and pavement.

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Disability glare is associated with veiling luminance caused by light from bright sources being scattered within the eyes of observers, thereby reducing retinal luminance contrast. This study compares the reduction in observers' performance in the presence of glare with veiling luminance in the eye, calculated using a nonsubjective method. A total of 42 observers performed a target detection task in the presence of a glare source in conditions similar to street lighting at night. Luminance contrast thresholds were measured for each observer under different levels of glare. Results show that, while veiling luminance has a significant effect on the performance of observers, its effect is lower than expected from contrast loss. Furthermore, the performance of observers over the age of 50 is unaffected by increasing the glare level. NotationA the age of the observer (years) C eff the effective luminance contrast of an object in the presence of glare C 0 the luminance contrast of an object in the absence of glare E eye the illuminance caused by a particular glare source at the observer's eye on a plane normal to the observer's direction of view (lx) k a disability glare model parameter, constant for a given observer L B the luminance of the background (cdÁm À2 ) L O the luminance of the object (cdÁm À2 ) L V the veiling luminance created by a particular visual environment (cdÁm À2 ) n a disability glare model parameter, constant for a given observer  the angle between the observer's direction of view and the glare source (8)

No abstract