Abstract: The function of road lighting is to prevent crime, provide a sense of perceived
personal safety, as well as the ability to successfully orientate and navigate urban
environments at night. However more and more people realize the negative effects of
abundant street lighting, such as light pollution and energy consumption. In 2001, 63 per cent
of the world population was confronted with night skies brighter than the threshold set for
light pollution by the International Astronomical Union (Chepesiuk, 2009). Exposure to light
pollution over longer periods of time can have lasting negative effects on the health of both
human and wildlife. A second motive for reducing abundant road lighting is sustainable
energy usage. The total energy consumption of public lighting in the Netherlands is currently
estimated to be 600.000 to 700.000 MWh a year, of which about 500.000 MWh is used for
the lighting of infrastructure such as roads, bicycle trials and footpaths (SenterNovem, 2009).
Reducing energy consumption and light pollution by road lighting can be realized using
intelligent dynamic road lighting systems with LED technology. Such intelligent dynamic
road lighting systems can offer light only when and where it is most needed, thereby
preventing light pollution and energy waste. However, such dynamic lighting should not
negatively affect a pedestrian’s perceived personal safety, because fear of crime often elicits a
stress reaction, to avoid, to reduce, or to cope with a threatening situation (Riger, 1985).
Therefore the addressed research question in this report is “What is the influence of different
dynamic road lighting scenarios on perceived personal safety” In particular, where would
pedestrian’s benefit from light the most e.g. at their own location or in their direct
surroundings?
To answer this research question a field study is performed using testbed “de Zaale”
on the campus of the Eindhoven University of Technology. “De Zaale” is normal street
setting equipped with intelligent dynamic road lighting containing twelve lampposts over a
range of 350 metres. A three condition (three different light distributions: darkspot, spotlight,
and a control condition) within-subject experiment was conducted with perceived personal
safety as the dependent variable. These three light scenarios are designed to have opposing
light distributions at the location of the pedestrian, with an equally amount of illumination.
To explain differences measured in perceived personal safety Appleton’s prospect and refuge
theory is used complemented with a social psychological model by van der Wurff and
colleagues (van der Wurff, Staalduinen & Stringer, 1989; Appleton, 1975). The dependant
variable perceived personal safety and the independent variables prospect, concealment,
exposure, escape, attractiveness and power are measured using an equidistant 5-point
answering scale questionnaire.
Considering the results the present study demonstrates that the manner in which light
is distributed across the poles in an intelligent dynamic road lighting setup influences the
perceived personal safety of pedestrians at night. We have shown in an experimental field
study that light has an effect on the proximal cues prospect, exposure, concealment and
escape. Prospect is indicated to be the most important proximal cue influencing a pedestrians
perceived personal safety. The relatively highest level of perceived personal safety is
experienced when a pedestrian’s personal and action space are sufficiently illuminated.
Illuminating these areas increases prospect, exposure an escape, and decreases concealment.
Additional illumination in a pedestrian’s vista space does not necessarily contribute to the
increase of their perceived personal safety. Furthermore individual differences between
pedestrians such as gender and attractiveness can enhance the negative effect of poorillumination on perceived personal safety. This knowledge should be integrated in the future
design of an intelligent dynamic road lighting system in order to maximise the personal safety
of pedestrians using such a system at night.