Comment on empirical evidence for the design of public lighting

A recent article (Peña-García et al., 2015) presented conclusions regarding the benefits of road lighting for pedestrians. Here it is demonstrated that those conclusions were drawn from incomplete evidence, in one case because the experimental designs leads only to a trivial solution and in a second case because of an incomplete search of the literature

Specifying enough light to feel reassured on pedestrian footpaths

This article discusses lighting for pedestrians and how investigation of reassurance might lead toward an understanding of the right amount of light. A conventional approach is to evaluate reassurance after dark under road lighting of different illuminance: this tends to show the trivial result that higher illuminances enhance reassurance, and that alone does not enable an optimum light level to be identified. One reason is that the category rating procedure widely used is prone to stimulus range bias; experimental results are presented that demonstrate stimulus range bias in reassurance evaluations. This article also recommends alternative methods for future research. One such method is the day–dark rating approach, which does not tend toward ever higher illuminances, and results are presented of two studies using this method