Outdoor Lighting and Crime - Amper

with lighting for an aging population. Blue light is also the worst possible choice if CCTV
cameras are in use as present image sensors are relatively insensitive to blue and violet light.
If the blue filters leak near-infrared light, as is often the case, the cameras have to be fitted
either with red filters or with expensive thin-film near-infrared rejection filters to avoid
double images from chromatic difference of magnification in the off-axis field.
Yet another snag with coloured lighting arises in the case of red light. Persons with the protan
colour vision deficiency, about 2% of males and 0.1% of females, are insensitive to red light,
regardless of the degree of colour confusion they exhibit. Depending on the shortest
wavelength of the available light, a red-lit area adequately bright for persons with another
colour vision deficiency or normal colour vision to move about in could effectively be quite
dark for protans. Red is therefore a poor choice for public lighting of any sort. Its impact on
crime would appear to be small because of its relatively low luminosity, unless colour
happens to be an effective factor in attractiveness of lighting hotspots.
If the need to discourage (displace?) drug injecting is important enough, low-pressure sodium
(LPS) lighting could be an economical compromise because of its extremely poor colour
rendering. Especially if the illuminance is kept at the lower end of the acceptable range and is
diffuse, LPS would tend to reduce vein visibility. Given that LPS lamps have a reputation for
occasional premature failure, installations using just a single lamp would need to be avoided.
Even a small amount of light from other sources would degrade the effectiveness of this
method, rather limiting its applicability to large areas without other kinds of lighting
(including vehicle headlights) or to fully enclosed areas without windows or gaps for natural
illumination in daytime. Most outdoor public conveniences (restrooms) would therefore be
less than ideal for LPS to be used as an anti-injecting measure. Extending Hodgson’s
comments above, the use of LPS with its noticeably different colour in a sea of other lighting
could be counterproductive. It would be different if LPS were in use generally in the area for
reasons of energy efficiency or minimising light pollution effects at nearby observatories. 99
7.7 DISCUSSION OF OUTDOOR LIGHTING STRATEGIES
7.7.1 Immediate actions: lighting trials and lighting moratoria
Based on this document alone, it would seem imprudent for governments to introduce
immediate large-scale reductions everywhere in outdoor lighting as a crime-reduction
measure. It would be just as imprudent to do nothing. Independent confirmation of the likely
benefits would appear essential. Paper studies could be valuable but successful results from
trial reductions of existing lighting would seem to be the only way in which sufficient
credibility could be gained to justify large-scale changes. Some towns are already well into
their own extended-duration trials of reduced lighting, albeit for budgetary reasons rather than
for crime reduction. Doubtless there will be opposition even to trials that might be seen as
massive threats to the comfortable status quo or cherished beliefs, but there is a strong prima
facie case for a crime-reduction outcome and the greater good must take precedence.
99 As mentioned in Sections 4.4.3 and 5.1, San Diego has decided to abandon its LPS street
lights in an attempt to make the streets safer at night. Most types of replacement lamps are
likely to be more suitable for illuminating illicit injections.
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