Program Goal/Target Population
Street lighting in
The area selected for relighting was identified by the local council on the basis of perceived need. The program targeted residents living, and offenders operating, on poorly lit estates. Targeted behaviors included increasing surveillance through increased pedestrian presence on the street, reducing offences through increased offender perception of risk, and increasing care-taking of the area through improved community spirit.
The key components of the program were the provision of lighting and lighting columns to provide luminosity that conformed to government set standards (BS 5489, Part 3). The lighting that was replaced did not even meet the minimum standard of the lowest of three lighting-standards categories. As a result, the new lighting created a fivefold increase in the amount of useful light.
From mid-December 1992 through mid-January 1993, domestic-type tungsten lamps were replaced by 110 high-pressure sodium street lights, which were installed over 1,000 meters of residential roadway at intervals of approximately 38 meters. Lighting was also installed on detached footpaths. The new lighting provided an average illuminance of 6 lux, with a minimum of 2.5 lux provided. The new installation almost doubled maintenance and energy costs.
The theory behind how and why street lighting works is comprehensively spelled out by situational crime prevention as well as crime prevention through environmental design (or CPTED). Specifically, increased lighting increases risks for offenders by increasing the likelihood of detection, both by formal surveillance systems and through natural surveillance. It also reduces the anonymity of offenders and increases risk of apprehension through facial identification. Street lighting can signal important investment in an area, which can strengthen informal social control and community cohesion.
Prevalence of Crime
The prevalence of crime decreased by 26 percent in the experimental area. All categories of crime, except burglary, declined significantly in the experimental area. The percentage of respondents who were victims of any crime also decreased by a quarter, from 57.7 percent to 42.8 percent. The prevalence of crime also decreased by 21 percent in the adjacent area, but this reduction was not statistically significant. Crime increased slightly, by 12 percent, in the control area.
Incidence of Crime
The incidence of crime decreased by 43 percent in the experimental area. The greatest decreases were for personal crime (68 percent) and vehicle crime (46 percent). The incidence of crime decreased by 45 percent in the adjacent area. Decreases in the adjacent area were significant for property crime (38 percent), personal crime (66 percent), and all crime (45 percent). The incidence of crime decreased by only 2 percent in the control area.
Vicarious Crime Experiences
Knowing crime victims and witnessing crimes decreased significantly in the experimental area. Prevalence also declined in the adjacent area (in some crime categories, these decreases were statistically significant). Generally, these rates increased in the control area.
Perceptions of Crime
Fear of crime as measured by surveys was not significantly reduced, although interviews indicated that residents felt safer and observations showed more people out at night in the experimental area.
Both prevalence and incidence of crime decreased in adjacent areas, indicating a diffusion effect. The study found no evidence of displacement.