Définir et mesurer
Les sources lumineuses
La Sécurité, criminalité
Définir et mesurer
Les sources lumineuses
La Sécurité, criminalité
This report, on street lighting, crime and fear, breaks fresh ground. Earlier work has been limited to short-term investigations of small areas, or even individual blackspots. The research presented here, which was carried out in the London Borough of Wandsworth, deals with the criminological impact of some 3,500 brighter street lights. The timeframe for ‘before’ and ‘after’ comparison was a full twelve months in each case, while the total database comprised over 100,000 crimes reported to the police. The team from the University of Southampton who carried out this research concluded that, as deployed on a broad scale, better street lighting has had little or no effect on crime. In their words, “the dominant overall conclusion … was of no significant change” On the other hand, they did find that the improved street lighting was warmly welcomed by the public, and that it provided a measure of reassurance to some people - particularly women – who were fearful in their use of public space. This report is perhaps slightly more technical than is usual in this series of Crime Prevention Unit Papers. To complement it, a readily accessible overview both of this and other relevant work has been prepared. That assessment, The Effect of Better Street Lighting on Crime and Fear: a Review, is being published at the same time as this report, as Crime Prevention Unit Paper 29.
We accept the evidence that lit roads are, generally, safer than unlit ones.23 We do not want a reduction in the length of lit roads but we do advocate the replacement of wasteful, light polluting old street and road lights with Full Cut Off lighting (see page 11). The overall length of motorway and A roads that are lit in the open countryside should not continue to grow. We recognise that there may be a few stretches of such road where a strong safety case can be made for an extension of lighting, but we argue that solar-powered LED cats’ eyes be considered as an alternative
The literature on fear of crime is extensive (Semmens 1999 ), although much of it is not about lighting. Other bibliographies (eg Nottingham 2001 ) provide additional material. Sherman et al. (1997)  has a critical review, including the use of lighting to allay fear. The widely accepted position is that people tend to fear crime more when they are in dark or dimly lit places, especially if there are no others or a small number of strangers about. In given circumstances, fear of crime is almost universally reported as being greater at night than it is by day, regardless of what the risks of actual crime are. Females are generally reported as being more fearful of crime than males. Survey data (eg Maguire and Pastore 2002, Table 2.4.1 ) tend to support these statements. It therefore reasonable to use artificial lighting to reduce fear of crime provided that this does not materially increase the risk of actual crime or cause some other adverse effect such as affecting driver vision or threatening biodiversity.
Scientific studies support common experience that light tends to allay the fear of crime at night. It is widely believed that outdoor lighting also helps prevent actual crime at night, but experiments have given equivocal results. Thorough scientific reviews published in 1977 and 1997 concluded that the effects were unknown. Recent work in the UK suggests that lighting does have a crime reducing effect by day as well as at night. This work appears to be flawed in ways that favour a crime-reducing result. While it seems reasonable to expect that social effects of outdoor lighting at night might have some influence on daytime crime, so far there appears to be no reliable evidence for any net crime-preventing effect, day or night. It even appears possible that lighting might increase crime, a topic investigated in Part 2 of this work. CCTV competes with outdoor lighting for crime-prevention funding. The available evidence indicates that CCTV is not an effective alternative. Until the lighting and crime issue is better understood, no more security lighting or other lighting for crime-prevention should be installed and the funding should be redirected to rectification of existing overbright and glary outdoor lighting.
Experimental evidence about the relationship between outdoor lighting and crime was examined in Part 1 of this work. Although the presence of light tends to allay the fear of crime at night, the balance of evidence from relatively short-term field studies is that increased lighting is ineffective for preventing or deterring actual crime. In this second part, available evidence indicates that darkness inhibits crime, and that crime is more encouraged than deterred by outdoor lighting. A new hypothesis is developed accordingly. Additional quantitative evidence supports the hypothesis. Excessive outdoor lighting appears to facilitate some of the social factors that lead to crime. The proliferation of artificial outdoor lighting has been fostered with little regard for the environmental consequences of wasteful practice. Widely observed exponential increases in artificial skyglow indicate that the growth of outdoor lighting is unsustainable. The natural spectacle of the night sky has already been obliterated for much of the population of the developed world. Copious artificial light has transformed civilisation, but increasing knowledge of its adverse environmental, biological and cultural effects now justifies large overall reductions in outdoor ambient light at night as well as in its waste component. ‘Good’ lighting has to be redefined. Moderation of outdoor ambient light levels may reduce crime in due course, as well as limiting the adverse environmental effects. Lighting controls might provide a means of limiting urbanisation and urban sprawl. National crime prevention policies, laws, lighting standards, architectural use of light and urban planning practice appear in need of fundamental changes.
There is too much literature on the subject for a complete survey here, and reliance has been placed on some existing reviews. Present views on the subject are polarised. Particular studies have been selected for mention to indicate why, and to facilitate resolution. Nearly all of the available material is from the USA and the UK. Useful formal studies have presumably been done in other countries but few indications of this were found in Internet searches or scans of reference lists in papers cited in this work. A more thorough search of the literature including eight large bibliographic databases by Farrington and Welsh (2002a,b) [34,35] produced a more extensive collection, but again mostly of UK and USA origin. A standard convention is followed in this document. If an increase in light is accompanied by an increase in crime, a positive correlation, it is called a positive association or effect, naturally. This possibility is not often mentioned in the crime prevention literature but if it is, it tends to be called a negative effect. To follow that usage here would be to perpetuate confusion. Increased crime accompanying increased light is therefore a positive association. A decrease in light accompanied by a decrease in crime is a positive association also. Increased light and decreased crime is a negative or inverse association, and so is decreased light and increased crime. Useful or beneficial effects are unambiguous - they mean a reduction of crime in any circumstances.
Common experience, confirmed by experiments, is that artificial light at night tends to allay the fear of crime. Any deterrent effect on actual crime is difficult to investigate with field studies, partly because of pervasive extraneous influences. Crime-reducing, nil, uncertain, and crime-increasing effects of light at night have variously been reported for night or day or both, separately or combined or both. Thorough scientific reviews published in 1977 and 1997 in the USA concluded that the effect of lighting on actual crime was unknown. Nevertheless, crime prevention practitioners there and elsewhere, and even some academics, have asserted for decades that lighting is an important weapon, or even the most important weapon, in the fight against crime. UK work published since 1997 has increased academic acceptance that crime prevention effects of lighting do apply in some circumstances, although this UK work has been criticised by others for its procedural and analytical shortcomings
This review summarises the findings of previous studies from both the USA and Britain on the effectiveness of improved street lighting on crime. Rigorous criteria were set for the inclusion of studies. These criteria were: that improvements in street lighting were the main intervention studied; that there was an outcome measure of crime; that crime levels before and after the intervention were measured; and that the studies included a comparable control area. A meta-analysis of the eligible studies found that improved street lighting led to significant reductions in crime and with an overall reduction in recorded crime of 20 per cent across all the experimental areas. The review assesses why street lighting has this impact on crime. The authors conclude that lighting increases community pride and confidence and strengthens informal social control and that this explains the recorded impacts, rather than increased surveillance or deterrent effects. The authors, however, suggest that these explanatory theories need to be tested more explicitly in future research and that there need to be further assessments of the impacts of different levels of illumination on crime. The authors conclude that improvements in street lighting offer a cost-effective crime reduction measure and should be considered an important element in situational crime reduction programmes.
Since the first cave dweller discovered fire, mankind has used light as a defence against animals and other predators. It is now simple and cheap to provide and operate outdoor lighting, which would have amazed our ancestors by the amount of light produced. Well designed, installed and maintained security lights bring comfort and well being to our lives providing us with a sense of security in our homes. However, much security lighting is installed without due consideration of its suitability for the task and its effect on neighbours and the environment. Domestic security lights should provide the minimum level of illumination necessary to light a property. Whilst you may be happy with a light that illuminates half the street your neighbours may not
Home Office counting rules divide domestic burglary into two crime categories; burglary in a dwelling (Home Office code number 28) and aggravated burglary in a dwelling (Home Office code number 29). 3. Police determine whether the offence is burglary or aggravated burglary at the time the crime is recorded and usually before it is investigated. These categories can then be flagged by the police on a discretionary basis with the following additions: − attempted; − with loss; − without loss; − repeat victimisation; − distraction burglary.
Crime prevention practitioners have always included lighting as part of their toolbox, and have advocated its use accordingly. However, over the last fifteen years there has emerged the view that street lighting does not have effects in reducing crime. Such a view has been attributed to the Home Office, with the result that many have taken it to be in some sense an official position. If left unchallenged, such a view would have the effect of excluding or limiting the role of street lighting in local crime and disorder prevention strategies required under the Crime and Disorder Act 1998. It was thus thought timely to consider the effect of street lighting on crime afresh. The Head of the Home Office Crime Prevention Agency, Chief Constable Richard Childs thus asked the writer to review the research evidence. The review was to be funded by the Lighting Industry Federation, but the writer, the Home Office and the Federation agreed on its independence, and that therefore publication of the review was not to be contingent on the conclusions reached. The review was undertaken in July-August 1998. The purpose of this note is to inform the reader of the general thrust of the review, and of the implications of the present state of knowledge. A copy of the full report is available from the ILE.
This paper shows that the reply by Profs Farrington and Welsh to my work “A demonstration that the claim that brighter lighting reduces crime is unfounded” still contains flaws and misunderstandings. A key element which is not accounted for is the spatial correlation of crime events in any one period of observation. This effect explains the high observed variability of the crime counts; much higher than is conceded in their reply to me; an order of magnitude greater than Poisson. The effect of ‘regression towards the mean’ is also one of their problems not properly dealt with. (The Protocol for a Campbell Collaboration systematic review is similarly flawed.) Any study using their methods will be subject to such errors. My work here will explain, in a relatively non-technical fashion, what the problems are. The problems uncovered are general, going beyond any specific evaluation, and can be readily seen with more extensive data from 124 areas.
A key issue for all science. Can research findings be plausibly explained by means other than that given by the original researcher? / Previous talk spoke of some of the potential artefacts that may be seriously afflicting lighting research…For example HORS251 / Strange ideas …. health care of old….
CRIME has fallen in the areas street lights have been switched off overnight, new figures reveal.
Burglaries, anti-social behaviour, vehicle crime, and violent crime have all fallen since the majority of Warwickshire’s street lights were turned off last year.
In April last year, most of the county’s street lights were switched off between midnight and 5.30am on weekdays, and 1am-6.30am on Saturday and Sunday mornings.
Warwickshire County Council, who had previously been spending £2.2 million on street lighting each year, wanted to save £500,000 and cut CO2 emissions.
A year on, the council has analysed the crime rate and number of accidents during the hours, and at the locations, street lights were switched off in Warwickshire.
Data for 2013/14 was compared to 2011/12 because that is the last full year the lights were on throughout the county.
Anti-social behaviour incidents fell 40.4%, from 1,308 to 779.
Domestic burglary was down 98 to 75, a fall of 23.5%.
Non-domestic burglary was down 26.9%, falling from 93 to 68.
Violent crime offences fell 20.6% from 330 to 262, and vehicle crime was down from 129 to 98, a reduction of 24%.
First published Monday 22 February 2010
By Chie Elliott and Rebecca Evans
CCTV cameras in Sussex are being hampered by street lights, The Argus can reveal.
Glare from lamps is causing such poor picture quality that individuals filmed committing a crime cannot be identified.
Despite admitting that street lighting can have a negative effect on crucial footage, police officers insist CCTV is still an “effective tool.”
MPs have now written to the force demanding an explanation.
The glitch came to light after three yobs filmed vandalising a shop could not be identified because of “glare” from street lamps.