Crime Reduction - Helping to Reduce Crime in Your Area

This review summarises the findings of previous studies carried out in the USA and Britain on the effect of improved street lighting on crime. Systematic reviews use specific methods for locating, appraising and producing evidence from previous evaluation studies, and have clear objectives and criteria together with extensive searches to locate possible relevant studies.

Title: Effects of improved street lighting on crime: a systematic review
Authors: David P Farrington & Brandon C Welsh
Series: Home Office Research Study 251
Date published: August 2002
Number of pages: 60

There are two main theories as to why improved street lighting may cause a reduction in crime. The first suggests that improved lighting leads to increased surveillance of potential offenders (by improving visibility and increasing the number of people on the street) and subsequently the deterrence of offenders. The other theory maintains that improved lighting indicates improved community investment in the area, leading to an increase in community pride and cohesiveness.

The studies included in this review had to meet specific criteria:

• if improved street lighting was the main intervention

• if there was an outcome measure of crime

• if there was at least one experimental area and one control area

• if there were before and after measures of crime

• if the total number of crimes in each area before the intervention was at least 20.

Sixteen potential case studies were obtained and screened but were excluded from the report due to a lack of comparable control conditions, the absence of an outcome measurement of crime and too small numbers. Most of these studies found that improved street lighting was followed by a decrease in crime.

Eight American and five British evaluation studies met the criteria. Four of the American studies found that improved street lighting was effective in reducing crime, while the other four had no effect. Combining together the results of all eight studies showed that improved street lighting led to a near-significant 7% decrease in crime. Results of the British studies showed that improved street lighting led to a 30% decrease in crime. Two studies made financial savings from reduced crimes, which exceeded the costs of the improved lighting.

All 13 studies showed that improved lighting led to reductions in crime, with an overall 20% reduction in crime in experimental areas compared with control areas.

The conclusions showed that improved lighting should be included as one element of a situational crime reduction programme. It is an inclusive intervention benefiting the whole of a neighbourhood and leads to an increase in perceived public safety. Improved street lighting is associated with greater use of public space and neighbourhood streets by the community.

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