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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It is well established that there are two main aspects to glare, the visual impairment and the discomfort, known as disability and discomfort glare, respectively. In contrast to the case of disability glare we understand very little about the underlying mechanisms or physiology of discomfort glare. This study attempts to elucidate the neural mechanisms involved using fMRI and glare sources with controlled levels of retinal illuminance. Prior to carrying out the fMRI experiment, we determined each participant's discomfort glare threshold. The participants were then divided into two groups of equal size based on their ranked sensitivity to discomfort glare, a low and high sensitivity group. In the fMRI experiment each participant was presented with three levels of glare intensity whilst simultaneously required to carry out a simple behavioral task. We compared BOLD responses between the two groups and found that the group more sensitive to glare had an increased response that was localized at three discrete, bilateral cortical locations: one in the cunei, one in the lingual gyri and one in the superior parietal lobules. This increased response was present for all light levels tested, whether or not they were intense enough to cause discomfort glare. Based on the results, we present the case that discomfort glare may be a response to hyperexcitability or saturation of visual neurons.

The paper reports a study that examines how to determine if a road traffic collision took place in daylight or in the dark. An innovative method was developed, based on solar altitude, to establish cut-off points of daylight and darkness determined from a study of daylight availability in England, Scotland and Wales. This approach provides a rigorous method to differentiate daytime and night-time collisions. The criteria were used in a study of the collisions reported in the STATS19 data set for the weeks either side of the clock changes that are necessary between Greenwich Mean Time and British Summer Time. By comparing periods with the same clock time either side of the time change, using the aforementioned method, it was possible to isolate collisions within the same time period that during one week occurred in darkness and in the other week in daylight. The initial finding was that there are 19.3% more collisions in the dark periods and there is an even greater increase (31.7%) in pedestrian injuries.

The current principles of road lighting design are well established and have been adopted in a number of lighting design standards. This paper questions the basis of these principles and looks at some of the anomalies and problems of current road lighting design practice. The development of road lighting for pedestrians is examined, and the benefits of having a relevant visual task are explored. The paper concludes by suggesting that the fundamentals of road lighting need further examination.