Outdoor Lighting and Crime - Amper

The new hypothesis suggests that present high rates of crime are partly a result of excessively
high outdoor ambient light levels at night. This was tested by examining the crime rate in
cities of Australia, Canada, England and the USA. For England and the USA (the two largest
available data sets), statistically significant positive correlations were found between crime
data and city upward light energy losses measured by satellites. A non-significant positive
trend was found for Canadian cities. The Australian crime data were inadequate and the
result was indeterminate.
The hypothesis also indicates that outdoor crime should be most prevalent in brightly lit rather
than dim locations. This was confirmed by illuminance measures at the locations of drugs
crime arrests in central Melbourne and by the increased crime at Melbourne metropolitan rail
stations since large increases in lighting were introduced. Light at night and crime are
positively correlated, whatever people say. Causality cannot be proved, but it is strongly
supported by a causal connection between imposed darkness and the reduced crime observed
in many small- and large-scale instances.
The scope for rectification is indicated by some cities having twenty or more times as much
outdoor light as others in terms of per person or per unit area. A citizen survey in one of the
relatively dim cities indicated acceptability of the installed lighting. Large reductions in
outdoor lighting are therefore justifiable for many other cities. The result expected is
reduction or reversal of the growth of urban crime and the pressure for growth in police and
criminal justice resources. Metropolitan growth at present is also encouraged by bright
outdoor lighting in urban and suburban shopping centres. Unless the accompanying growth in
motivation and opportunity for crime, or at least some types of crime, is accepted as an
inevitable cost of metropolitan development, fundamental changes are needed in outdoor
lighting practice and in urban and regional planning principles.
Urbanisation, urban sprawl and crime appear controllable simply by limiting the absolute
levels of ambient artificial light permitted outdoors. Desirable demographic changes may be
achievable with lighting restrictions tailored to specific areas. Existing safety, health and
environmental knowledge already justifies reductions in the total amount of outdoor lighting.
The case for fixed lighting as a traffic accident countermeasure needs reassessment. The
contribution of vehicle lighting to ambient light at night may need to be reduced.
Dimming or removal of much existing outdoor lighting should be possible while glare
reduction techniques help to maintain adequate levels of visibility, mobility and traffic safety,
and the feeling of personal safety. Some present lighting practices such as decorative lighting
and illumination of advertisements may have to be severely constrained if not abandoned
entirely. Escape of indoor light should be blocked at night, especially from high buildings.
Present architectural practices with lighting and glass-walled buildings need to be re-directed.
Developing countries will add to the pressure for equitable caps on national lighting energy
use.
National and regional laws, standards and strategies for sustainable outdoor lighting are sorely
needed. ‘Good’ lighting needs to be redefined. Outcomes should include avoidance of
substantial waste of national, corporate, individual and natural resources on misguided and
counterproductive schemes that currently require more and brighter lighting supposedly to
reduce crime while actually increasing it.
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