MERLIN: Mesopically Enhanced Road Lighting: Improving Night-vision

这个项目将研究如何改变住宅区道路的照明，以保持良好视觉的好处，同时最大限度地减少能源消耗。在住宅道路中，道路照明主要是为了满足行人的需求而设计的。道路照明对行人的好处是增强了安全移动(例如，增加了潜在旅行危险的可见性)和感知安全。将能源消耗降至最低还将降低运营成本和碳排放。英国的道路照明每年消耗2.5TWh的电力，其中约三分之一与住宅街道有关(其余为主干道照明、标志和护柱)。典型的单位成本为0.10/千瓦时，这意味着每年的成本超过8300万英镑。照明技术的最新进展和我们对中间视觉的理解有可能改善照明的光谱功率分布(SPD)和空间分布的规范，以实现降低照明水平，从而降低能源消耗，同时保持甚至提高效益水平。通过更好地规范住宅街道照明标准，将是改进照明设计从而节省能源的直接途径。这将通过对英国标准BS5489-1的修订来实现：其中两名申请者在国家和国际道路照明标准化机构任职，因此能够实施这些修订。与国际惯例相比，英国使用的灯光水平可能过高。在英国，住宅街道的照明平均为2到15勒克斯的路面照度。然而，澳大利亚的平均照度往往只有0.5到0.85勒克斯，而日本的平均照度为3到5勒克斯。因此，降低英国的光照水平显然是有潜力的。该项目包括三个主要阶段。首先，我们建议识别和描述行人在夜间的主要视觉任务，以及他们认为重要的视觉环境的主要方面。这将通过分析当前住宅道路上的行人环境来确定：将进行眼球跟踪研究，以确定夜间行走时看到的是什么物体，并将进行保证研究，以确定街道的空间和光度特征如何影响感知的安全性。据我们所知，“对行人重要的是什么”这一根本问题并不是以往任何研究的重点。为第二阶段提出的工作将确定这些关键视觉任务如何受到照明水平、光谱功率分布和照明的空间分布的影响。这将在两个平行的研究中进行检查；(I)检查阈值视觉反应，和(Ii)检查应用任务的表现，如面部识别。最后阶段将根据项目中获得的数据，确定住宅街道照明设计的最佳标准，从而确定最佳照度和光源特性。随后，我们将利用这个项目将产生的优化设计标准，通过重新照明住宅街道样本，向最终用户演示和验证实施新发现的好处。由于这项工作将取决于以前的调查结果，而且由于需要与地方当局达成协议，该项目的这一部分已安排为后续活动。照明设备制造商已经同意捐赠这项工作所需的大部分设备。

This project will investigate how the lighting of roads in residential areas might be changed so as to preserve the benefits of good vision while minimising energy consumption. In residential roads the road lighting is designed primarily to meet the needs of pedestrians. Benefits of road lighting for the pedestrian are enhancement of safe movement (e.g. increased visibility of potential trip hazards) and perceived safety. Minimising energy consumption will also reduce operating costs and carbon emissions. Road lighting in the UK consumes 2.5TWh electricity per annum, of which approximately one third is associated with residential streets (the remainder being trunk route lighting, signs and bollards). At a typical unit cost of 0.10/kWh this represents an annual cost of over 83 million. Recent advances in lighting technology and in our understanding of mesopic vision have the potential to improve specification of the spectral power distribution (SPD) and spatial distribution of lighting to achieve reductions in the level of illumination, and hence a reduction in energy consumption, whilst maintaining or even improving the level of benefits. A direct route to improved lighting design and thus energy savings will be through better specification of residential street lighting criteria. This will be realised by amendments to British Standard BS5489-1: two of the applicants serve on national and international standardisation bodies for road lighting and so are able to implement such amendments.Comparison with international practise suggests that light levels used in the UK may be excessive. In the UK, residential streets are lit to average pavement illuminances in the range 2 to 15 lux. However, Australia tends to use average illuminances of only 0.5 to 0.85 lux, and 3 to 5 lux in Japan. Thus there is clear potential to reduce light levels in the UK.The project involves three major stages. First, we propose to identify and characterise the principal visual tasks of pedestrians at night-time and the key aspects of the visual environment they consider to be important. This will be established by analysing the pedestrian environment on current residential roads: an eye tracking study will be carried out to determine what objects are viewed when walking at night-time together with a reassurance study to determine how the spatial and photometric characteristics of streets affect perceived safety. To our knowledge, the fundamental question of 'What is important to pedestrians' has not been the focus of any previous research. The work proposed for the second stage will identify how these critical visual tasks are affected by the level of illumination, spectral power distribution and spatial distribution of lighting. This will be examined in two parallel studies; (i) an examination of threshold visual responses, and (ii) an examination of the performance of applied tasks, such as facial recognition. The final stage will determine the optimum criteria for lighting design in residential streets and hence the optimum illuminances and light source properties based on the data obtained in the project. We will subsequently demonstrate and validate the benefits of implementing the new findings to end users by re-lighting a sample of residential streets using the optimised design criteria that will emerge from this project. Because this work will be dependant upon the previous findings and because it requires agreement with local authorities this part of the project has been scheduled as a follow-up activity. Agreement has already been obtained from lighting equipment manufacturers to donate much of the equipment needed for this work.