Lighting : LIGHTING-June-July-2017
LETTERS T O THE EDIT OR Criminal friendly lighting and a false sense of security I refer to the article published in the February/March issue (pp22-25). While I agree with some of the information in the article I believe that the presentation is somewhat sensational and the conclusions do not necessarily arise from the facts. I suspect that there is more of a Dark Sky agenda, whilst important, than a desire to improve night-time safety or to promote the responsible use of public money. Much of the research into public lighting and crime has been carried out by sociologists or criminologists who, while being experts in their subject, have limited expertise in lighting and therefore, take a very simplistic view of lighting. Assessments are usually made on the basis of average illumination levels or recommended levels with little regard for the quality of the installations. I agree that lighting does not reduce crime. I have never heard anyone say that they were giving up a life of crime because the lighting was too bright. Unfortunately, there is a misconception, particularly by some public authorities, that the solution to all crime is to keep increasing the lighting levels. With all lighting there is a diminishing scale of returns and once you have achieved an adequate illumination level for the task, increasing the illumination level gives less and less additional performance. So how does lighting reduce crime? We need to separate security lighting from public lighting as they are separate issues. When public lighting refers to the risk of crime it is talking about crime in public spaces. It is not referring to crime in general. It refers to the actual risk of crime, the vulnerability of the situation and the perception of personal safety. The main role of public lighting is to enhance natural surveillance. This works in two ways. Firstly, if the space is well lit and comfortable to be in, then there is a higher chance that people will be in the space. The presence of people and adequate lighting increases the chance that any potential offence will be witnessed, which shifts the risk/benefit of the crime away from the perpetrator. June/July 2017 | LIGHTING MAGAZINE 9 Q&A Criminal-friendly lighting BY PENNY JONES If you have to walk outdoors at night, the chances are you prefer well-lit routes over dark ones. The feeling that light equals safety is so ubiquitous that it comes as a bit of a shock when you discover your feelings of safety are probably illusory; and, worse still, well-lit areas can actually encourage criminal behaviour. Dr Barry Clark is a successful human factors researcher. He has studied the controversial topic of lighting and crime. As we will see in this Q&A, he is passionate about the need for people to understand that popular belief about lighting and crime has been shown to be a myth. WHAT IS THE LIGHTING AND CRIME MYTH? Longstanding conventional wisdom is that lighting things up at night makes an area safer. However, there is no reliable scientific evidence for this. In fact, my research indicates a small adverse effect. HOW SO? In 2002-3, I published a two-part report called Outdoor Lighting and Crime. In the first part, a literature analysis indicated that increasing light at night can certainly allay the fear of crime but the effect on preventing or deterring actual crime was uncertain. The second part relied on published crime statistics for dozens of cities around the world for which satellite measurements of light intensity were also available. The results contradicted conventional belief: at typical levels of street lighting, tenfold increases in lighting reliably produce increases around a few percent in the crime rate. Six weeks after I put my scientific reputation on the line by releasing 22 LIGHTING MAGAZINE | February/March 2017 the second part, there was a great blackout in the north-eastern states of the USA and Canada. In accordance with my findings there was a marked decrease in crime throughout the affected area. Studies in the UK and US have since confirmed that crime is not increased when street lighting is reduced. Regardless, Australian lighting standards continue to specify brighter illumination when the perceived or known risk of crime is higher. Unfortunately, this helps perpetuate the myth of lighting for safety and security while actually facilitating crime at night. It also opposes economic and environmental reasons to reduce outdoor lighting. WHY DO YOU THINK THIS IS? Lighting for safety is so ingrained that often when reductions in outdoor ambient light flux at night are proposed, people throw up their hands in horror and say “I feel unsafe at night without a lot of light”, but it’s a false sense of security. February/March 2017 | LIGHTING MAGAZINE 23 and a false sense of security Figure 1. The luminaire uses a ceramic metal halide lamp in a spherical luminaire. (All images from Illinois Coalition for Responsible Outdoor Lighting, USA) Figure 2. The”Victorian” acorn-shaped luminaire uses a high-pressure sodium.
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